Specific Process Knowledge/Etch/DRIE-Pegasus/Pegasus-4/SiO2 Etch/Cr mask: Difference between revisions

From LabAdviser
Jump to navigation Jump to search
 
(21 intermediate revisions by the same user not shown)
Line 50: Line 50:
|'''Temporary conclusions on how the process parameters affect the results in this study:'''
|'''Temporary conclusions on how the process parameters affect the results in this study:'''
|'''What process parameters affect the results?'''
|'''What process parameters affect the results?'''
|-
|- style="vertical-align:top;"
|
|
*Going from full wafer to small piece on Si carrier:  
*Going from full wafer to small piece on Si carrier:  
Line 84: Line 84:
|}
|}
===Profile SEM images===
===Profile SEM images===
{| border="2" cellspacing="2" cellpadding="3"  
{| border="2" cellspacing="2" cellpadding="3" style="width: 100%;"  
!Recipe settings
!style="width: 20%"|Recipe settings
!Comments
!style="width: 10%"|Comments
!SEM gallery
!style="width: 70%"|SEM gallery
|-
|- style="vertical-align:top;"
|
|
*'''On 6" wafer'''
*'''On 6" wafer'''
Line 111: Line 111:
File:C09721_center_22.jpg
File:C09721_center_22.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*'''Piece on Si carrier'''
*'''Piece on Si carrier'''
Line 134: Line 134:
File:C10022_03__12.jpg
File:C10022_03__12.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*Coil Power [W]:2500
*Coil Power [W]:2500
Line 145: Line 145:
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
|Less sidewall passivation from removing the H2
|
|
|text
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm" perrow="6" widths="200px" heights="150px">
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm" perrow="6" widths="200px" heights="150px">
File:C10025_03__11.jpg
File:C10025_03__11.jpg
Line 155: Line 155:
File:C10025_03__01.jpg
File:C10025_03__01.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*Coil Power [W]:2500
*Coil Power [W]:2500
Line 167: Line 167:
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
|Not a large effect from adding a little O2
|
|
|text
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, O2:5sccm" perrow="6" widths="200px" heights="150px">
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, O2:5sccm" perrow="6" widths="200px" heights="150px">
File:C10026_03__05.jpg
File:C10026_03__05.jpg
Line 177: Line 177:
File:C10026_03__10.jpg
File:C10026_03__10.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*Coil Power [W]:2500
*Coil Power [W]:2500
Line 189: Line 189:
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
|Reducing total flow rate and thereby the pressure gives less passivation/redeposition. Sidewall roughness not so bad.
|
|
|text
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:225sccm, Pressure:3.35mTorr" perrow="6" widths="200px" heights="150px">
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:225sccm, Pressure:3.35mTorr" perrow="6" widths="200px" heights="150px">
File:C10082_11.jpg
File:C10082_11.jpg
Line 202: Line 202:
File:C010082tilt30_13.jpg
File:C010082tilt30_13.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*'''Coil Power [W]:1200'''
*'''Coil Power [W]:1200'''
Line 214: Line 214:
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
|Reducing the coil power a lot and platen power a little gives more sidewall passivation/redeposition
|
|
|text
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:225sccm, Pressure:3.35mTorr; platen power 150W, coil power:1200W" perrow="6" widths="200px" heights="150px">
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:225sccm, Pressure:3.35mTorr; platen power 150W, coil power:1200W" perrow="6" widths="200px" heights="150px">
File:C10084_15.jpg
File:C10084_15.jpg
Line 224: Line 224:
File:C10084_03.jpg
File:C10084_03.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*Coil Power [W]:1200
*Coil Power [W]:1200
Line 236: Line 236:
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
|Adding oxygen reduces the passivation/redeposition
|
|
|text
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:215sccm O2:10sccm, Pressure:3.6mTorr; platen power 150W, coil power:1200W" perrow="6" widths="200px" heights="150px">
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:215sccm O2:10sccm, Pressure:3.6mTorr; platen power 150W, coil power:1200W" perrow="6" widths="200px" heights="150px">
File:C10093_03__11.jpg
File:C10093_03__11.jpg
Line 246: Line 246:
File:C10093_03__01.jpg
File:C10093_03__01.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*Coil Power [W]:1200
*Coil Power [W]:1200
Line 258: Line 258:
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
|Adding more oxygen reduces further the passivation/redeposition but some trenching appears.
|
|
|text
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.6mTorr; platen power 150W, coil power:1200W" perrow="7" widths="200px" heights="150px">
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.6mTorr; platen power 150W, coil power:1200W" perrow="7" widths="200px" heights="150px">
File:C10101_03__12.jpg
File:C10101_03__12.jpg
Line 269: Line 269:
File:C10101_03__14.jpg
File:C10101_03__14.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*'''Coil Power [W]:1800'''
*'''Coil Power [W]:1800'''
Line 281: Line 281:
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
|Increasing coil power reduces trenching but increases passivation/redeposition
|
|
|text
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:215sccm O2:10sccm, Pressure:3.6mTorr; platen power 150W, coil power:1800W" perrow="6" widths="200px" heights="150px">
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:215sccm O2:10sccm, Pressure:3.6mTorr; platen power 150W, coil power:1800W" perrow="6" widths="200px" heights="150px">
File:C10102_03__05.jpg
File:C10102_03__05.jpg
Line 291: Line 291:
File:C10102_03__16.jpg
File:C10102_03__16.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*Coil Power [W]:1800
*Coil Power [W]:1800
Line 303: Line 303:
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
|Adding more O2 reduces the sidewall passivation/redeposition
|
|
|text
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.6mTorr; platen power 150W, coil power:1800W" perrow="6" widths="200px" heights="150px">
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.6mTorr; platen power 150W, coil power:1800W" perrow="6" widths="200px" heights="150px">
File:C10110_04.jpg
File:C10110_04.jpg
Line 312: Line 312:
File:C10110_12.jpg
File:C10110_12.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*'''Coil Power [W]:1200'''
*'''Coil Power [W]:1200'''
Line 324: Line 324:
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN  
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN  
|Running with the lower coil power and reducing the platen power also seems to reduced the sidewall passivatin/redeposition, but etch rate goes down
|
|
|text
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.6mTorr; platen power 100W, coil power:1200W" perrow="7" widths="200px" heights="150px">
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.6mTorr; platen power 100W, coil power:1200W" perrow="7" widths="200px" heights="150px">
File:C10119_01.jpg
File:C10119_01.jpg
Line 334: Line 334:
File:C10119_11.jpg
File:C10119_11.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*Coil Power [W]:1200
*Coil Power [W]:1200
Line 346: Line 346:
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN  
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN  
|Repeating with longer etch time to etch 1500 nm down. Unfortunately this damaged the hardware due to the EM coils getting too hot. 
|
|
|text
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier '''14 min etch''' (PLEASE DO NOT REPEAT THIS LONG TIME), H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.6mTorr; platen power 100W, coil power:1200W" perrow="7" widths="200px" heights="150px">
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier '''14 min etch''' (PLEASE DO NOT REPEAT THIS LONG TIME), H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.6mTorr; platen power 100W, coil power:1200W" perrow="7" widths="200px" heights="150px">
File:C10160_02.jpg
File:C10160_02.jpg
Line 357: Line 357:
File:Contour Plot Y32 EM_02_30 blue to red.jpg| Etch on none patterned wafer, Uniformity: +- 6.4%
File:Contour Plot Y32 EM_02_30 blue to red.jpg| Etch on none patterned wafer, Uniformity: +- 6.4%
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*'''Coil Power [W]:1800'''
*'''Coil Power [W]:1800'''
Line 369: Line 369:
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'  
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN  
*PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN  
|Running 1800W/150W at increased time to etch down to 1500 nm.
|
|
|text
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier '''10 min etch''', H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.6mTorr; platen power 150W, coil power:1800W" perrow="6" widths="200px" heights="150px">
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier '''10 min etch''', H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.6mTorr; platen power 150W, coil power:1800W" perrow="6" widths="200px" heights="150px">
File:C10161_01.jpg
File:C10161_01.jpg
Line 381: Line 381:
File:C010161tilt_04.jpg
File:C010161tilt_04.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*'''Coil Power [W]:1200'''
*'''Coil Power [W]:1200'''
Line 392: Line 392:
*Pressure:Fully open APC valve (3.9 mTorr)
*Pressure:Fully open APC valve (3.9 mTorr)
*'''Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A''''  
*'''Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A''''  
|Repeating the 1200W/100W recipes at 14 min but without the EM coils. For this recipe the uniformity over the wafer improved from removing the EM coils, so no need for those and now the recipe could run 14 min without damaging the hardware. The profile looked as before. After removing the Cr I looked from the top and with a tilted view and saw the the sidewall roughness was very bad. 
|
|
|text
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 14 min etch, EM:0/0 H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.9mTorr; platen power 100W, coil power:1200W" perrow="7" widths="200px" heights="150px">
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 14 min etch, EM:0/0 H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.9mTorr; platen power 100W, coil power:1200W" perrow="7" widths="200px" heights="150px">
File:C10184_01.jpg
File:C10184_01.jpg
Line 409: Line 409:
File:C010184tilt20plasmaO2_05.jpg| tilt 20 degrees
File:C010184tilt20plasmaO2_05.jpg| tilt 20 degrees
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*'''Coil Power [W]:2500'''
*'''Coil Power [W]:2500'''
Line 420: Line 420:
*Pressure:Fully open APC valve (3.9 mTorr)
*Pressure:Fully open APC valve (3.9 mTorr)
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'  
|Tried high coil power and low platen power. This seemed to give som undercutting,especially on the narrow lines. The smallest has been etched away. The etch rate was very low
|
|
|text
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 14 min etch, EM:0/0 H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.9mTorr; platen power 100W, coil power:2500W" perrow="7" widths="200px" heights="150px">
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 14 min etch, EM:0/0 H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.9mTorr; platen power 100W, coil power:2500W" perrow="7" widths="200px" heights="150px">
File:C10381_04.jpg
File:C10381_04.jpg
Line 429: Line 429:
File:C10381_30dg_21.jpg
File:C10381_30dg_21.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*Coil Power [W]:2500
*Coil Power [W]:2500
Line 435: Line 435:
*Platen temperature [<sup>o</sup>C]: 20
*Platen temperature [<sup>o</sup>C]: 20
*H2 flow [sccm]:0
*H2 flow [sccm]:0
*O2 flow [sccm]: 0
*'''O2 flow [sccm]: 0'''
*C<sub>4</sub>F<sub>8</sub> flow [sccm]: 13.0
*C<sub>4</sub>F<sub>8</sub> flow [sccm]: 13.0
*He flow [sccm]:225
*He flow [sccm]:225
*Pressure:Fully open APC valve (3.9 mTorr)
*Pressure:Fully open APC valve (3.9 mTorr)
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'  
|Increasing the platen power and and removing the oxygen helped on the under cutting but the lines are still very narrow at the bottom. It also increased the etch rate
|
|
|text
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 14 min etch, EM:0/0 H2:0sccm, C4F8:13sccm He:225sccm O2:0sccm, Pressure:3.9mTorr; platen power 200W, coil power:2500W" perrow="7" widths="200px" heights="150px">
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 14 min etch, EM:0/0 H2:0sccm, C4F8:13sccm He:225sccm O2:0sccm, Pressure:3.9mTorr; platen power 200W, coil power:2500W" perrow="7" widths="200px" heights="150px">
File:C10393_04.jpg
File:C10393_04.jpg
Line 451: Line 451:
File:C10393_16.jpg
File:C10393_16.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*'''14 min'''
*'''14 min'''
Line 463: Line 463:
*Pressure:Fully open APC valve (3.9 mTorr)
*Pressure:Fully open APC valve (3.9 mTorr)
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'  
|Adding the oxygen again further increased the etch rate and reduced the CD (Critical Dimension) of the Cr mask.
|
|
|text
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 14 min etch, EM:0/0 H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.9mTorr; platen power 200W, coil power:2500W" perrow="7" widths="200px" heights="150px">
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 14 min etch, EM:0/0 H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.9mTorr; platen power 200W, coil power:2500W" perrow="7" widths="200px" heights="150px">
File:C10399_01.jpg
File:C10399_01.jpg
Line 473: Line 473:
File:C10399_13.jpg
File:C10399_13.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*'''Back to start setting without EM coils - 14 min'''
*'''Back to start setting without EM coils - 14 min'''
Line 485: Line 485:
*Pressure:Fully open APC valve (8-9 mTorr)
*Pressure:Fully open APC valve (8-9 mTorr)
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'  
|I repeated the start setting but without the EM coils. This gives a very none uniform etch over the wafer where in some parts it deposites instead of etching. The profile of 800 nm oitch look fairly good but a closer look reveals the the sidewall is very rough from either redeposition or polymerization. this cannot be removed with a O2 plasma.
|
|
|text
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 14 min etch, EM:0/0" perrow="7" widths="200px" heights="150px">
<gallery caption="SiO2 etch with Cr mask on wafer piece on Si carrier 14 min etch, EM:0/0" perrow="7" widths="200px" heights="150px">
File:C10576_02.jpg
File:C10576_02.jpg
Line 498: Line 498:
File:C10576_17.jpg
File:C10576_17.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*'''Coil Power [W]:600'''
*'''Coil Power [W]:600'''
Line 509: Line 509:
*Pressure:Fully open APC valve ('''<2 mTorr''')
*Pressure:Fully open APC valve ('''<2 mTorr''')
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'  
|Due to the large sidewall roughness I decided to try and run at lower powers because it looked at some images like an ionbonbardment effect. First try with 600W/50W. The profile looks fairly good but still with some sidewall roughness. there is also some trenching and the Cr mask looks has a facet all the way down to the SiO2. The is also some bowing.
|
|
|text
<gallery caption=" C10751: SiO2 etch with Cr mask on wafer piece on Si carrier 20 min etch, EM:0/0 H2:0sccm, C4F8:6.5sccm He:100sccm O2:10sccm, Pressure:?mTorr; platen power 50W, coil power:600W" perrow="7" widths="200px" heights="150px">
<gallery caption=" C10751: SiO2 etch with Cr mask on wafer piece on Si carrier 20 min etch, EM:0/0 H2:0sccm, C4F8:6.5sccm He:100sccm O2:10sccm, Pressure:?mTorr; platen power 50W, coil power:600W" perrow="7" widths="200px" heights="150px">
File:C10751_02.jpg
File:C10751_02.jpg
Line 519: Line 519:
File:C10751_12.jpg
File:C10751_12.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*'''Coil Power [W]:300'''
*'''Coil Power [W]:300'''
Line 530: Line 530:
*Pressure:Fully open APC valve (<2 mTorr)
*Pressure:Fully open APC valve (<2 mTorr)
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'  
|Even lower powers: 300W/25W. The profiles looks better with less roughness but also mush slower etch rate, so not as deep as the previous.
|
|
|text
<gallery caption=" C10752: SiO2 etch with Cr mask on wafer piece on Si carrier 30 min etch, EM:0/0 H2:0sccm, C4F8:6.5sccm He:100sccm O2:10sccm, Pressure:?mTorr; platen power 25W, coil power:300W" perrow="6" widths="200px" heights="150px">
<gallery caption=" C10752: SiO2 etch with Cr mask on wafer piece on Si carrier 30 min etch, EM:0/0 H2:0sccm, C4F8:6.5sccm He:100sccm O2:10sccm, Pressure:?mTorr; platen power 25W, coil power:300W" perrow="6" widths="200px" heights="150px">
File:C10752_01.jpg
File:C10752_01.jpg
Line 540: Line 540:
File:C10752_10.jpg
File:C10752_10.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*'''45 min'''
*'''45 min'''
Line 552: Line 552:
*Pressure:Fully open APC valve (<2 mTorr)
*Pressure:Fully open APC valve (<2 mTorr)
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'  
|Repeating with longer etch time. Low sidewall roughness, less faceting of the Cr mask. Still some trenching and bowing or negative tapering of the profile.
|
|
|text
<gallery caption=" C10834: SiO2 etch with Cr mask on wafer piece on Si carrier 45 min etch, EM:0/0 H2:0sccm, C4F8:6.5sccm He:100sccm O2:10sccm, Pressure:?mTorr; platen power 25W, coil power:300W" perrow="6" widths="200px" heights="150px">
<gallery caption=" C10834: SiO2 etch with Cr mask on wafer piece on Si carrier 45 min etch, EM:0/0 H2:0sccm, C4F8:6.5sccm He:100sccm O2:10sccm, Pressure:?mTorr; platen power 25W, coil power:300W" perrow="6" widths="200px" heights="150px">
File:C10834_12.jpg
File:C10834_12.jpg
Line 568: Line 568:
File:C10834T_22.jpg
File:C10834T_22.jpg
</gallery>
</gallery>
|-
|- style="vertical-align:top;"
|
|
*Coil Power [W]:300
*Coil Power [W]:300
Line 579: Line 579:
*Pressure:Fully open APC valve (<2 mTorr)
*Pressure:Fully open APC valve (<2 mTorr)
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'  
*Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'  
|Decreased the platen power a little to see if this could remove the trenching. Not much different from the last.
|
|
|text
<gallery caption=" C10844: SiO2 etch with Cr mask on wafer piece on Si carrier 50 min etch, EM:0/0 H2:0sccm, C4F8:6.5sccm He:100sccm O2:10sccm, Pressure:?mTorr; platen power 20W, coil power:300W" perrow="6" widths="200px" heights="150px">
<gallery caption=" C10844: SiO2 etch with Cr mask on wafer piece on Si carrier 50 min etch, EM:0/0 H2:0sccm, C4F8:6.5sccm He:100sccm O2:10sccm, Pressure:?mTorr; platen power 20W, coil power:300W" perrow="6" widths="200px" heights="150px">
File:C10844_02.jpg
File:C10844_02.jpg

Latest revision as of 12:35, 8 February 2024

Feedback to this page: click here
Unless otherwise stated, all content in this section was done by Berit Herstrøm, DTU Nanolab

SiO2 trench etching with Cr mask

Start parameters, variations noted in the gallery headline Recipe name: no 10 with lower platen power
Coil Power [W] 2500
Platen Power [W] 200
Platen temperature [oC] 20
H2 flow [sccm] 25.6
C4F8 flow [sccm] 25.6
He flow [sccm] 448.7
Pressure Fully open APC valve (8-9 mTorr)
Electromagnetic coils (EM) 'outer coil' / 'inner coil' '2 A' / '30 A' (PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN)
  • 100 nm Cr mask etched in ICP metal with 500nm DUV neg resist (NUV 2300-0.5) and 65 nm barc.
Cr mask before SiO2 etch 800 nm pitch 50% duty cycle. The The Cr linewidth is clearly less than designed


Results

Temporary conclusions on how the process parameters affect the results in this study: What process parameters affect the results?
  • Going from full wafer to small piece on Si carrier:
    • Seemed to give more sidewall passivation
  • Platen power: lowering the platen power gives
    • more sidewall passivation
    • lower etch rate
    • Less trenching
  • Removing the H2 gave:
    • less sidewall passivation
  • Adding O2 gave:
    • less sidewall passivation
  • Process pressure/total gasflow rate
    • Reducing total gasflow rate which reduced the pressur inside the chamber gave:
      • less sidewall passivation
      • Reduced the CD (Critical Dimensions)
  • Coil power: Reducing coil power
    • less CD loss
    • more sidewall passivation
  • Increasing process time:
    • less sidewall passivation
    • more sidewall bow
    • CD loss due to larger mask faceting
  • Sidewall passivation↑
    • Sample size↓
    • Platen power↓
    • Coil power↓
    • H2 flow↑
    • O2 flow↓
    • Total gas flow rate/pressure↑

Profile SEM images

Recipe settings Comments SEM gallery
  • On 6" wafer
  • Coil Power [W]:2500
  • Platen Power [W]: 200
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:25.6
  • C4F8 flow [sccm]: 25.6
  • He flow [sccm]:448.7
  • Pressure:Fully open APC valve (8-9 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'
  • PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
 text
  • SiO2 etch with Cr mask on full wafer 6 min etch
  • C09721 center 10.jpg
  • C09721 center 18.jpg
  • C09721 center 21.jpg
  • C09721 center 07.jpg
  • C09721 center 05.jpg
  • C09721 center 22.jpg
  • Piece on Si carrier
  • Coil Power [W]:2500
  • Platen Power [W]: 200
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:25.6
  • C4F8 flow [sccm]: 25.6
  • He flow [sccm]:448.7
  • Pressure:Fully open APC valve (8-9 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'
  • PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
 More sidewall passivation on chip than on full wafer
  • SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch
  • C10022 03 06.jpg
  • C10022 03 04.jpg
  • C10022 03 02.jpg
  • C10022 03 08.jpg
  • C10022 03 10.jpg
  • C10022 03 12.jpg
  • Coil Power [W]:2500
  • Platen Power [W]: 200
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • C4F8 flow [sccm]: 25.6
  • He flow [sccm]:448.7
  • Pressure:Fully open APC valve (8-9 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'
  • PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
 Less sidewall passivation from removing the H2
  • SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm
  • C10025 03 11.jpg
  • C10025 03 09.jpg
  • C10025 03 07.jpg
  • C10025 03 05.jpg
  • C10025 03 03.jpg
  • C10025 03 01.jpg
  • Coil Power [W]:2500
  • Platen Power [W]: 200
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 5
  • C4F8 flow [sccm]: 25.6
  • He flow [sccm]:448.7
  • Pressure:Fully open APC valve (8-9 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'
  • PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
 Not a large effect from adding a little O2
  • SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, O2:5sccm
  • C10026 03 05.jpg
  • C10026 03 03.jpg
  • C10026 03 01.jpg
  • C10026 03 07.jpg
  • C10026 03 09.jpg
  • C10026 03 10.jpg
  • Coil Power [W]:2500
  • Platen Power [W]: 200
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 0
  • C4F8 flow [sccm]: 13.0
  • He flow [sccm]:225
  • Pressure:Fully open APC valve (3.35 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'
  • PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
 Reducing total flow rate and thereby the pressure gives less passivation/redeposition. Sidewall roughness not so bad.
  • SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:225sccm, Pressure:3.35mTorr
  • C10082 11.jpg
  • C10082 09.jpg
  • C10082 07.jpg
  • C10082 05.jpg
  • C10082 03.jpg
  • C10082 01.jpg
  • C010082top 07.jpg
  • C010082top 03.jpg
  • C010082tilt30 13.jpg
  • Coil Power [W]:1200
  • Platen Power [W]: 150
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 0
  • C4F8 flow [sccm]: 13.0
  • He flow [sccm]:225
  • Pressure:Fully open APC valve (3.35 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'
  • PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
 Reducing the coil power a lot and platen power a little gives more sidewall passivation/redeposition
  • SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:225sccm, Pressure:3.35mTorr; platen power 150W, coil power:1200W
  • C10084 15.jpg
  • C10084 13.jpg
  • C10084 11.jpg
  • C10084 09.jpg
  • C10084 06.jpg
  • C10084 03.jpg
  • Coil Power [W]:1200
  • Platen Power [W]: 150
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 10
  • C4F8 flow [sccm]: 13.0
  • He flow [sccm]:215
  • Pressure:Fully open APC valve (3.35 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'
  • PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
 Adding oxygen reduces the passivation/redeposition
  • SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:215sccm O2:10sccm, Pressure:3.6mTorr; platen power 150W, coil power:1200W
  • C10093 03 11.jpg
  • C10093 03 09.jpg
  • C10093 03 07.jpg
  • C10093 03 05.jpg
  • C10093 03 03.jpg
  • C10093 03 01.jpg
  • Coil Power [W]:1200
  • Platen Power [W]: 150
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 20
  • C4F8 flow [sccm]: 13.0
  • He flow [sccm]:205
  • Pressure:Fully open APC valve (3.35 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'
  • PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
 Adding more oxygen reduces further the passivation/redeposition but some trenching appears.
  • SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.6mTorr; platen power 150W, coil power:1200W
  • C10101 03 12.jpg
  • C10101 03 10.jpg
  • C10101 03 07.jpg
  • C10101 03 05.jpg
  • C10101 03 03.jpg
  • C10101 03 01.jpg
  • C10101 03 14.jpg
  • Coil Power [W]:1800
  • Platen Power [W]: 150
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 10
  • C4F8 flow [sccm]: 13.0
  • He flow [sccm]:215
  • Pressure:Fully open APC valve (3.35 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'
  • PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
 Increasing coil power reduces trenching but increases passivation/redeposition
  • SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:215sccm O2:10sccm, Pressure:3.6mTorr; platen power 150W, coil power:1800W
  • C10102 03 05.jpg
  • C10102 03 03.jpg
  • C10102 03 01.jpg
  • C10102 03 20.jpg
  • C10102 03 18.jpg
  • C10102 03 16.jpg
  • Coil Power [W]:1800
  • Platen Power [W]: 150
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 20
  • C4F8 flow [sccm]: 13.0
  • He flow [sccm]:205
  • Pressure:Fully open APC valve (3.6 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'
  • PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
 Adding more O2 reduces the sidewall passivation/redeposition
  • SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.6mTorr; platen power 150W, coil power:1800W
  • C10110 04.jpg
  • C10110 06.jpg

  • pitch 800 nm
    Top 461 nm
    @edge 437 nm
    bottom 402 nm
    height 916 nm
    height from edge 827 nm
    Cr left 83.5 nm
    selectivity 55.5

  • 156 nm/min

  • C10110 12.jpg
  • Coil Power [W]:1200
  • Platen Power [W]: 100
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 20
  • C4F8 flow [sccm]: 13.0
  • He flow [sccm]:205
  • Pressure:Fully open APC valve (3.6 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'
  • PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
 Running with the lower coil power and reducing the platen power also seems to reduced the sidewall passivatin/redeposition, but etch rate goes down
  • SiO2 etch with Cr mask on wafer piece on Si carrier 6 min etch, H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.6mTorr; platen power 100W, coil power:1200W
  • C10119 01.jpg
  • C10119 03.jpg

  • pitch 800 nm
    Top 444 nm
    bottom 374 nm
    height 718 nm
    Cr left 85 nm
    selectivity 48

  • C10119 06.jpg
  • C10119 09.jpg
  • C10119 11.jpg
  • Coil Power [W]:1200
  • Platen Power [W]: 100
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 20
  • C4F8 flow [sccm]: 13.0
  • He flow [sccm]:205
  • Pressure:Fully open APC valve (3.6 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'
  • PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
 Repeating with longer etch time to etch 1500 nm down. Unfortunately this damaged the hardware due to the EM coils getting too hot.
  • SiO2 etch with Cr mask on wafer piece on Si carrier 14 min etch (PLEASE DO NOT REPEAT THIS LONG TIME), H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.6mTorr; platen power 100W, coil power:1200W
  • C10160 02.jpg
  • C10160 06.jpg
  • C10160 09.jpg
  • C10160 12.jpg
  • C10160 15.jpg
  • C10160 17.jpg

  • Etch on none patterned wafer, Uniformity: +- 6.4%

  • Coil Power [W]:1800
  • Platen Power [W]: 150
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 20
  • C4F8 flow [sccm]: 13.0
  • He flow [sccm]:205
  • Pressure:Fully open APC valve (3.6 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'2 A' / '30 A'
  • PLEASE DO NOT RUN WITH THESE SETTINGS FOR MORE THAN 6 MIN
 Running 1800W/150W at increased time to etch down to 1500 nm.
  • SiO2 etch with Cr mask on wafer piece on Si carrier 10 min etch, H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.6mTorr; platen power 150W, coil power:1800W
  • C10161 01.jpg
  • C10161 03.jpg
  • C10161 05.jpg
  • C10161 07.jpg
  • C10161 09.jpg
  • C10161 11.jpg
  • C010161top 01.jpg
  • C010161tilt 04.jpg
  • Coil Power [W]:1200
  • Platen Power [W]: 100
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 20
  • C4F8 flow [sccm]: 13.0
  • He flow [sccm]:205
  • Pressure:Fully open APC valve (3.9 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'
 Repeating the 1200W/100W recipes at 14 min but without the EM coils. For this recipe the uniformity over the wafer improved from removing the EM coils, so no need for those and now the recipe could run 14 min without damaging the hardware. The profile looked as before. After removing the Cr I looked from the top and with a tilted view and saw the the sidewall roughness was very bad.
  • SiO2 etch with Cr mask on wafer piece on Si carrier 14 min etch, EM:0/0 H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.9mTorr; platen power 100W, coil power:1200W
  • C10184 01.jpg
  • C10184 05.jpg
  • C10184 07.jpg
  • C10184 09.jpg
  • C10184 11.jpg
  • C10184 12.jpg

  • Etch on none patterned wafer, Uniformity: +-1.7%

  • C010184top 01.jpg
  • C010184top 04.jpg

  • tilt 30 degrees

  • tilt 30 degrees

  • tilt 20 degrees

  • tilt 20 degrees

  • Coil Power [W]:2500
  • Platen Power [W]: 100
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 20
  • C4F8 flow [sccm]: 13.0
  • He flow [sccm]:205
  • Pressure:Fully open APC valve (3.9 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'
 Tried high coil power and low platen power. This seemed to give som undercutting,especially on the narrow lines. The smallest has been etched away. The etch rate was very low
  • SiO2 etch with Cr mask on wafer piece on Si carrier 14 min etch, EM:0/0 H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.9mTorr; platen power 100W, coil power:2500W
  • C10381 04.jpg
  • C10381 06.jpg
  • C10381 07.jpg
  • C10381 30dg 17.jpg
  • C10381 30dg 21.jpg
  • Coil Power [W]:2500
  • Platen Power [W]: 200
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 0
  • C4F8 flow [sccm]: 13.0
  • He flow [sccm]:225
  • Pressure:Fully open APC valve (3.9 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'
 Increasing the platen power and and removing the oxygen helped on the under cutting but the lines are still very narrow at the bottom. It also increased the etch rate
  • SiO2 etch with Cr mask on wafer piece on Si carrier 14 min etch, EM:0/0 H2:0sccm, C4F8:13sccm He:225sccm O2:0sccm, Pressure:3.9mTorr; platen power 200W, coil power:2500W
  • C10393 04.jpg
  • C10393 06.jpg
  • C10393 09.jpg
  • C10393 11.jpg
  • C10393 12.jpg
  • C10393 14.jpg
  • C10393 16.jpg
  • 14 min
  • Coil Power [W]:2500
  • Platen Power [W]: 200
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 20
  • C4F8 flow [sccm]: 13.0
  • He flow [sccm]:205
  • Pressure:Fully open APC valve (3.9 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'
 Adding the oxygen again further increased the etch rate and reduced the CD (Critical Dimension) of the Cr mask.
  • SiO2 etch with Cr mask on wafer piece on Si carrier 14 min etch, EM:0/0 H2:0sccm, C4F8:13sccm He:205sccm O2:20sccm, Pressure:3.9mTorr; platen power 200W, coil power:2500W
  • C10399 01.jpg
  • C10399 02.jpg
  • C10399 04.jpg
  • C10399 08.jpg
  • C10399 10.jpg
  • C10399 13.jpg
  • Back to start setting without EM coils - 14 min
  • Coil Power [W]:2500
  • Platen Power [W]: 200
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:25.6
  • O2 flow [sccm]: 0
  • C4F8 flow [sccm]: 25.6
  • He flow [sccm]:448.7
  • Pressure:Fully open APC valve (8-9 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'
 I repeated the start setting but without the EM coils. This gives a very none uniform etch over the wafer where in some parts it deposites instead of etching. The profile of 800 nm oitch look fairly good but a closer look reveals the the sidewall is very rough from either redeposition or polymerization. this cannot be removed with a O2 plasma.
  • SiO2 etch with Cr mask on wafer piece on Si carrier 14 min etch, EM:0/0
  • C10576 02.jpg
  • C10576 01.jpg
  • C10576 04.jpg
  • C10576 06.jpg
  • C10576 08.jpg
  • C10576 10.jpg
  • C10576 19.jpg
  • C10576 22.jpg
  • C10576 17.jpg
  • Coil Power [W]:600
  • Platen Power [W]: 50
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 10
  • C4F8 flow [sccm]: 6.5
  • He flow [sccm]:100
  • Pressure:Fully open APC valve (<2 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'
 Due to the large sidewall roughness I decided to try and run at lower powers because it looked at some images like an ionbonbardment effect. First try with 600W/50W. The profile looks fairly good but still with some sidewall roughness. there is also some trenching and the Cr mask looks has a facet all the way down to the SiO2. The is also some bowing.
  • C10751: SiO2 etch with Cr mask on wafer piece on Si carrier 20 min etch, EM:0/0 H2:0sccm, C4F8:6.5sccm He:100sccm O2:10sccm, Pressure:?mTorr; platen power 50W, coil power:600W
  • C10751 02.jpg
  • C10751 05.jpg
  • C10751 07.jpg
  • C10751 09.jpg
  • C10751 11.jpg
  • C10751 12.jpg
  • Coil Power [W]:300
  • Platen Power [W]: 25
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 10
  • C4F8 flow [sccm]: 6.5
  • He flow [sccm]:100
  • Pressure:Fully open APC valve (<2 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'
 Even lower powers: 300W/25W. The profiles looks better with less roughness but also mush slower etch rate, so not as deep as the previous.
  • C10752: SiO2 etch with Cr mask on wafer piece on Si carrier 30 min etch, EM:0/0 H2:0sccm, C4F8:6.5sccm He:100sccm O2:10sccm, Pressure:?mTorr; platen power 25W, coil power:300W
  • C10752 01.jpg
  • C10752 03.jpg
  • C10752 05.jpg
  • C10752 07.jpg
  • C10752 09.jpg
  • C10752 10.jpg
  • 45 min
  • Coil Power [W]:300
  • Platen Power [W]: 25
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 10
  • C4F8 flow [sccm]: 6.5
  • He flow [sccm]:100
  • Pressure:Fully open APC valve (<2 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'
 Repeating with longer etch time. Low sidewall roughness, less faceting of the Cr mask. Still some trenching and bowing or negative tapering of the profile.
  • C10834: SiO2 etch with Cr mask on wafer piece on Si carrier 45 min etch, EM:0/0 H2:0sccm, C4F8:6.5sccm He:100sccm O2:10sccm, Pressure:?mTorr; platen power 25W, coil power:300W
  • C10834 12.jpg
  • C10834 10.jpg
  • C10834 08.jpg
  • C10834 06.jpg
  • C10834 02.jpg
  • C10834 04.jpg
  • C10834T 17.jpg
  • C10834T 15.jpg
  • C10834T 20.jpg
  • C10834T 19.jpg
  • C10834T 21.jpg
  • C10834T 22.jpg
  • Coil Power [W]:300
  • Platen Power [W]: 20
  • Platen temperature [oC]: 20
  • H2 flow [sccm]:0
  • O2 flow [sccm]: 10
  • C4F8 flow [sccm]: 6.5
  • He flow [sccm]:100
  • Pressure:Fully open APC valve (<2 mTorr)
  • Electromagnetic coils (EM) 'outer coil' / 'inner coil':'0 A' / '0 A'
 Decreased the platen power a little to see if this could remove the trenching. Not much different from the last.
  • C10844: SiO2 etch with Cr mask on wafer piece on Si carrier 50 min etch, EM:0/0 H2:0sccm, C4F8:6.5sccm He:100sccm O2:10sccm, Pressure:?mTorr; platen power 20W, coil power:300W
  • C10844 02.jpg
  • C10844 05.jpg
  • C10844 09.jpg
  • C10844 07.jpg
  • C10844 11.jpg
  • C10844 13.jpg
Retrieved from "https://labadviser.nanolab.dtu.dk//index.php?title=Specific_Process_Knowledge/Etch/DRIE-Pegasus/Pegasus-4/SiO2_Etch/Cr_mask&oldid=49362"