Specific Process Knowledge/Etch/DRIE-Pegasus/processA: Difference between revisions

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Effects on Process A of showerhead change in December 2014

The effects of changing of the showerhead in December 2014 was investigated. Patterned wafers were processed before and after and the profile of the etched features were inspected in SEM. Click on the numbers in the 'Runs' column below to see the profiles.

Recipe	Name	Temp.	Deposition step						Etch step							Comments
Recipe	Name	Temp.	Time	Pres.	C₄F₈	SF₆	O₂	Coil	Time	Pres.	C₄F₈	SF₆	O₂	Coil	Platen	Showerhead	Runs	Key words
Process A	Step1 11 cyc	20	4	25	200	0	0	2000	7.0	25(1.5s) 90>>150	0	350(1.5s) 550	5	2800	120>>140(1.5s) 45	Old	1
	Step2 44 cyc	20	4	25	200	0	0	2000	7.0	25(1.5s) 150	0	350(1.5s) 550	5	2800	140(1.5s) 45	Old	1
	Step1 11 cyc	20	4	25	200	0	0	2000	7.0	25(1.5s) 90>>150	0	350(1.5s) 550	5	2800	120>>140(1.5s) 45	New	1	Profile improved
	Step2 44 cyc	20	4	25	200	0	0	2000	7.0	25(1.5s) 150	0	350(1.5s) 550	5	2800	140(1.5s) 45	New	1	Profile improved

Process A test

Process A is intended as a wide trench (80μm wide) depth etched down some 150 µm. Below are the results from a run on a 150 mm wafer with 12-13 % etch load.

**Process A specifications**
Parameter	Specification	Average result
Etch rate (µm/min)	> 15	18.9
Etched depth (µm)	150	189.1
Scallop size (nm)	< 800	718
Profile (degs)	91 +/- 1	91.1
Selectivity to AZ photoresist	> 150	310
Undercut (µm)	<1.5	0.84
Uniformity (%)	< 3.5	3.0
Repeatability (%)	<4	0.43

	Process A parameters
	Step 1		Step 2
Parameter	Etch	Dep	Etch	Dep
Gas flow (sccm)	SF₆ 350 (1.5 s) 550	C₄F₈ 200	SF₆ 350 (1.5 s) 550	C₄F₈ 200
Cycle time (secs)	7.0	4.0	7.0	4.0
Pressure (mtorr)	25 (1.5 s) 90 >> 150	25	25 (1.5 s) 150	25
Coil power (W)	2800	2000	2800	2000
Platen power (W)	120 >> 140 (1.5) 45	0	140 (1.5) 45	0
Cycles	11 (keep fixed)		44 (vary this)
Common	Temperature 20 degs, HBC 10 torr, Short funnel, with baffle & 5mm spacers

Quality control procedure

Quality Control (QC) for DRIE-Pegasus

QC Recipe:	Process A
QC Recipe:	Step 1: 11 cycles		Step 2: 44 cycles

QC limits	DRIE-Pegasus
Etch rate in Si	16 - 18.8 µm/min
Non-uniformity	2 %

Process A guidelines

Process A is optimized for speed and depending on feature size and etch load it will achieve etch rates up to 25-30 µm/min.

This aggressive etch has a few drawbacks - one of which is the release of energy in the etch process. In general, it is clear that

The higher the etch rate, the higher rate of released energy.
The larger an area of silicon is exposed to plasma and hence etched, the higher rate of released energy.

Given its high etch rate, Process A is very sensible to high etch load processes and substrates with reduced cooling efficiency. Therefore, users are generally advised to

Use Process A with precaution at high etch loads - above some 50%.
Avoid using Process A on bonded wafers, in particular if the etch load is more than 5-10%. The bonding reduces the heat conduction across the wafer interface so the top wafer will immediately heat up and cause the mask to erode and the bonding polymer to melt.

If you have a bonded sandwich of wafers with very poor heat conduction (typically caused by intermediate polymer layers thicker than a few microns) you are advised to use other etch processes, maybe the deepetch on the ASE.

Process A performance

The perfomance of Process A has been investigated as a function of feature size and etch load.

Experiment

A number of wafers are patterned with the Travka mask set in AZ photoresist or 600 nm oxide. The wafers are then etched (batch recipe with 5 minute TDESC interstep cleans) using two different durations of process A in the DRIE-Pegasus.

**Wafers**
Wafer number	Mask	Mask material	Process A duration
C01548.01	Travka 05	AZ photoresist	55 cycles, 10:05 mins
C01548.02	Travka 10	AZ photoresist	55 cycles, 10:05 mins
C01548.03	Travka 20	AZ photoresist	55 cycles, 10:05 mins
C01548.04	Travka 35	AZ photoresist	55 cycles, 10:05 mins
C01548.05	Travka 50	AZ photoresist	55 cycles, 10:05 mins

**Wafers**
Wafer number	Mask	Mask material	Process A duration
C01549.01	Travka 05	600 nm oxide	110 cycles, 20:10 mins
C01549.02	Travka 10	600 nm oxide	110 cycles, 20:10 mins
C01549.03	Travka 20	600 nm oxide	110 cycles, 20:10 mins
C01549.04	Travka 35	600 nm oxide	110 cycles, 20:10 mins

Results: Optical images

Optical images of the C01548 batch that is processed 10:05 mins.
Wafer C01548.01: 5 % exposed area
Wafer C01548.02: 10 % exposed area
Wafer C01548.03: 20 % exposed area
Wafer C01548.04: 35 % exposed area
Wafer C01548.05: 50 % exposed area
File:Without pre-etch measurements of the thicknesses of the photoresist it is not possible to determine the resist etch rate. However, it looks very uniform.

Optical images of the C01549 batch that is processed 20:10 mins.
Wafer C01549.01: 5 % exposed area. Some 190 nm of 600 nm oxide remains.
Wafer C01549.02: 10 % exposed area. Some 122 nm oxide remains.
Wafer C01549.03: 20 % exposed area. In the centre some 90 nm oxide remains.
Wafer C01549.04: 35 % exposed area. In the centre some 90 nm oxide remains.
Wafer C01549.05: 35 % exposed area (close-up). The oxide has disappeared leaving the Si exposed.

The etching of silicon releases energy. This means that the faster the etch is, the more heat needs to be dissipated. The consequence is the same if a larger percentage of the wafer is etched. Process A is the fastest etch and as seen above, the exposed area plays an important role. As the exposed area increases the oxide mask erosion is more and more pronounced.

If a larger area is to be etched, the cooling must be made more efficient, either by lowering the platen temperature or with increasing the pressure of He on the backside of the wafer. This will be investigated soon.

Results: Etched depths in trenches of different widths

Graphs
Process time 10:05
Process time 20:10

Results: SEM images of trench cross sections

Travkatesting2: Process A run for 55 cycles on travka 5, 10, 20, 35, 50 masks

Date

Substrate Information

Process Information

SEM images of trenches

2 µm

3 µm

4 µm

6 µm

8 µm

10 µm

15 µm

25 µm

40 µm

50 µm

75 µm

100 µm

150 µm

200 µm

300 µm

January 2013

Travka05, AZ 5214, 5% open

Process A 55 cycles or 10:05 minutes, C01548.01

Trench width	2	3	4	6	8	10	15	25	40	50	75	100	150	200	300
Etched depth (µm)	92	106	113	126	136	146	161	181	200	208	222	230	238	243	248
Av. ER (µm/min)	9,2	10,5	11,2	12,5	13,5	14,4	16,0	18,0	19,9	20,7	22,0	22,8	23,6	24,1	24,6
Av. ER (nm/cyc)	1679	1918	2054	2294	2473	2648	2933	3299	3641	3786	4038	4184	4324	4409	4507
Sdewll bowing (%)	0,3%	0,2%	0,2%	0,3%	0,3%	0,2%	0,0%	0,2%	0,2%	-0,3%	0,1%	0,1%	0,2%	0,2%	-0,1%
Sdewll angle(degs)	90,4	90,3	90,5	90,8	90,6	90,9	91,0	90,9	90,9	91,0	90,9	90,9	91,1	91,2	91,4
Trench width (µm)	4,8	7,1	7,7	9,7	12,6	14,1	20,0	30,3	46,3	56,4	82,5	107,3	156,9	206,7	308,6

January 2013

Travka10, AZ 5214, 10% open

Process A 55 cycles or 10:05 minutes, C01548.02

Trench width (µm)	2	3	4	6	8	10	15	25	40	50	75	100	150	200	300
Etched depth (µm)	90	101	108	121	130	138	152	171	189	198	210	218	228	232	239
Av. ER (µm/min)	8,9	10,0	10,7	12,0	12,9	13,7	15,1	16,9	18,8	19,6	20,9	21,6	22,6	23,1	23,7
Av. Scllp hght (nm)	1639	1834	1964	2192	2356	2508	2772	3103	3441	3601	3825	3961	4143	4227	4346
Sdwall bowing (%)	0,40	0,19	0,25	0,16	0,04	0,12	0,16	-0,18	-0,04	0,00	0,04	-0,08	-0,20	-0,05	-0,05
Sdwall angle (degs)	90,2	90,3	90,5	90,5	90,6	90,7	90,8	91,1	91,1	91,1	91,1	91,2	91,2	91,3	91,6
Trench width (µm)	5,2	7,2	8,2	10,9	13,2	15,5	20,6	31,3	46,5	56,1	81,2	107,2	158,9	211,1	306,2

January 2013

Travka20, AZ 5214, 20% open

Process A 55 cycles or 10:05 minutes, C01548.03

Trench width (µm)	2	3	4	6	8	10	15	25	40	50	75	100	150	200	300
Etched depth (µm)	75	85	92	103	111	117	130	148	164	170	181	188	194	199	203
Av. ER (µm/min)	7,5	8,4	9,1	10,2	11,0	11,6	12,9	14,7	16,2	16,8	17,9	18,6	19,3	19,7	20,1
Av. Scllp hght (nm)	1371	1543	1676	1874	2019	2133	2368	2692	2978	3086	3286	3412	3533	3619	3686
Sdwall bowing (%)	0,46	0,59	0,40	0,42	0,40	0,28	0,35	0,18	0,36	0,36	0,26	0,58	0,40	0,31	0,05
Sdwall angle (degs)	90,1	90,4	90,4	90,5	90,8	90,6	91,1	91,3	91,4	91,5	91,5	91,7	91,8	91,8	92,2
Trench width (µm)	4,9	6,1	7,8	10,4	12,2	14,9	19,9	30,5	46,3	57,4	82,3	106,6	158,1	209,0	309,7

January 2013

Travka35, AZ 5214, 35% open

Process A 55 cycles or 10:05 minutes, C01548.04

Trench width (µm)	2	3	4	6	8	10	15	25	40	50	75	100	150	200	300
Etched depth (µm)	61	70	76	86	94	100	111	126	139	143	153	158	163	165	168
Av. ER (µm/min)	6,1	6,9	7,6	8,6	9,3	9,9	11,0	12,5	13,8	14,2	15,2	15,6	16,2	16,4	16,7
Av. Scllp hght (nm)	1117	1267	1390	1568	1704	1810	2014	2287	2526	2602	2786	2868	2967	3007	3054
Sdwall bowing (%)	0,22	0,31	0,30	0,46	0,39	0,55	0,41	0,20	-0,04	-0,33	-0,25	-0,19	-0,13	-0,13	-0,21
Sdwall angle (degs)	89,7	90,1	90,2	90,4	90,5	90,4	90,2	89,9	90,0	89,9	90,2	90,4	90,8	90,9	91,3
Trench width (µm)	4,5	5,4	6,7	9,0	11,4	13,4	19,1	30,0	45,0	56,2	82,3	108,4	156,3	207,5	308,3

January 2013

Travka50, AZ 5214, 50% open

Process A 55 cycles or 10:05 minutes, C01548.05

Trench width (µm)	2	3	4	6	8	10	15	25	40	50	75	100	150	200	300
Etched depth (µm)		62	67	75	81	86	94	105	113	118	123	125	129	131	133
Av. ER (µm/min)		6,2	6,7	7,5	8,0	8,5	9,3	10,4	11,2	11,7	12,2	12,4	12,8	13,0	13,2
Av. Scllp hght (nm)		1132	1223	1370	1472	1565	1706	1906	2061	2142	2234	2277	2355	2379	2412
Sdwall bowing (%)		0,42	0,61	0,39	0,36	0,41	0,38	0,39	0,52	0,24	0,36	0,47	0,63	0,59	0,32
Sdwall angle (degs)		89,9	89,8	90,0	90,1	90,5	90,7	91,1	91,3	91,6	91,8	92,1	92,3	92,4	92,6
Trench width (µm)		5,1	6,7	9,3	11,4	13,7	18,6	29,0	44,5	54,4	80,5	106,7	156,9	207,4	310,1

Travkatesting2: Process A run for 110 cycles on travka 5, 10, 20, 35 masks

Date

Substrate Information

Process Information

SEM images of trenches

2 µm

3 µm

4 µm

6 µm

8 µm

10 µm

15 µm

25 µm

40 µm

50 µm

75 µm

100 µm

150 µm

200 µm

300 µm

January 2013

Travka05, 600 nm oxide, 5% open

Process A 110 cycles or 20:10 minutes, C01549.01

Trench width (µm)	2	3	4	6	8	10	15	25	40	50	75	100	150	200	300
Etched depth (µm)	175	195	209	229	247	260	289	330	370	393	428	454	488	507	523
Av. ER (µm/min)	8,7	9,7	10,4	11,3	12,3	12,9	14,4	16,3	18,3	19,5	21,2	22,5	24,2	25,2	25,9
Av. Scllp hght (nm)	1591	1772	1902	2079	2247	2359	2631	2997	3364	3569	3888	4124	4434	4614	4751
Sdwall bowing (%)	0,12	0,20	0,30	0,35	0,32	0,35	0,40	0,30	0,41	0,24	0,33	0,32	0,47	0,71	0,00
Sdwall angle (degs)	89,6	89,9	89,9	90,1	90,2	90,3	90,7	90,9	91,1	91,4	91,5	91,5	91,2	91,6	91,7
Trench width (µm)	8,5	9,5	10,8	13,2	16,0	18,4	22,6	33,0	48,0	57,5	82,7	106,8	159,0	207,0	306,8

January 2013

Travka10, 600 nm oxide, 10% open

Process A 110 cycles or 20:10 minutes, C01549.02

Trench width (µm)	2	3	4	6	8	10	15	25	40	50	75	100	150	200	300
Etched depth (µm)	164	179	190	209	224	238	263	300	337	358	388	404	438	452	469
Av. ER (µm/min)	8,1	8,9	9,4	10,4	11,1	11,8	13,1	14,9	16,7	17,7	19,2	20,0	21,7	22,4	23,2
Av. Scllp hght (nm)	1489	1626	1730	1899	2034	2163	2395	2724	3063	3251	3526	3671	3978	4110	4262
Sdwall bowing (%)	0,20	0,41	0,46	0,57	0,74	0,62	0,68	0,75	0,58	0,99	0,54	0,49	0,72	0,51	0,77
Sdwall angle (degs)	89,7	90,0	89,9	90,1	90,2	90,3	90,8	91,2	91,5	91,3	92,0	92,2	92,6	92,8	93,6
Trench width (µm)	7,9	8,7	10,4	12,6	16,1	18,1	22,8	33,5	49,3	58,1	83,1	108,6	157,0	207,1	301,3

January 2013

Travka20, 600 nm oxide, 20% open

Process A 110 cycles or 20:10 minutes, C01549.03

Trench width (µm)	2	3	4	6	8	10	15	25	40	50	75	100	150	200	300
Etched depth (µm)	142	153	164	181	195	206	228	258	287	303	326	342	366	380	392
Av. ER (µm/min)	7,0	7,6	8,1	9,0	9,7	10,2	11,3	12,8	14,2	15,0	16,2	17,0	18,2	18,8	19,4
Av. Scllp hght (nm)	1288	1390	1493	1647	1775	1877	2073	2342	2612	2754	2967	3108	3331	3451	3561
Sdwall bowing (%)	0,54	0,77	1,08	0,83	1,06	0,91	0,95	1,07	0,88	0,75	0,95	0,05	0,83	0,73	0,46
Sdwall angle (degs)	89,6	89,6	89,8	90,2	90,3	90,6	90,9	91,5	91,6	91,8	92,3	93,3	92,5	92,9	93,0
Trench width (µm)	7,2	8,7	9,9	12,4	14,7	16,9	22,8	31,1	48,4	58,0	81,9	108,6	160,4	209,9	311,1

January 2013

Travka35, 600 nm oxide, 35% open

Process A 110 cycles or 20:10 minutes, C01549.04

Trench width (µm)	2	3	4	6	8	10	15	25	40	50	75	100	150	200	300
Etched depth (µm)			131	146	155	164	181	205	226	234	254	264	277	284	292
Av. ER (µm/min)			6,5	7,2	7,7	8,2	9,0	10,2	11,2	11,6	12,6	13,1	13,8	14,1	14,5
Av. Scllp hght (nm)			1189	1325	1408	1495	1642	1867	2050	2125	2312	2398	2523	2584	2653
Sdwall bowing (%)			1,35	1,37	1,25	1,28	1,24	1,45	1,30	1,42	1,50	1,38	1,18	0,76	0,81
Sdwall angle (degs)			89,4	89,6	89,9	90,0	90,3	91,0	91,7	91,9	92,3	92,4	93,0	93,0	93,5
Trench width (µm)			8,8	11,3	13,5	16,0	21,2	31,1	46,3	56,5	81,2	108,0	157,7	210,0	310,4

@@ Line 1: / Line 1: @@
 '''Feedback to this page''': '''[mailto:labadviser@nanolab.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.nanolab.dtu.dk/index.php/Specific_Process_Knowledge/Etch/DRIE-Pegasus/processA click here]'''
 <!--Checked for updates on 2/10-2020 - ok/jmli -->
+<!--Checked for updates on 28/6-2023 - ok/jmli -->
+{{contentbydryetch}}
 == Effects on Process A of showerhead change in December 2014 ==
@@ Line 104: / Line 107: @@
 |}
-== Process A acceptance test==
+== Process A test==
-Process A is labelled Large trench (80μm wide) 150μm depth. In the acceptance test the process was run on a 150 mm SPTS wafer with 12-13 % etch load.
+Process A is intended as a wide trench (80μm wide) depth etched down some 150 µm. Below are the results from a run on a 150 mm wafer with 12-13 % etch load.
 {| border="2" cellpadding="2" cellspacing="1" style="text-align:center;"
@@ Line 229: / Line 232: @@
 |-
 |Etch rate in Si
-|21 - 28 µm/min
+|16 - 18.8 µm/min
 |-
 |Non-uniformity
@@ Line 360: / Line 363: @@
 === Results: SEM images of trench cross sections ===
 {| border="2" cellpadding="0" cellspacing="0" style="text-align:center;"
@@ Line 368: / Line 372: @@
 ! width="50" rowspan="2"| Process Information
 ! colspan="15"| SEM images of trenches
-! rowspan="2" | Numbers
 |-
 ! 2 µm
@@ Line 386: / Line 389: @@
 ! 300 µm
 |-
-| January 2013
+|rowspan="2"| January 2013
-| Travka05, AZ 5214, '''5% open'''
+|rowspan="2"| Travka05, AZ 5214, '''5% open'''
-| Process A 55 cycles or 10:05 minutes, '''C01548.01'''
+|rowspan="2"| Process A 55 cycles or 10:05 minutes, '''C01548.01'''
 | [[file:C01548.01 002mu0025.jpg |75px|frameless ]]
 | [[file:C01548.01 003mu0026.jpg |75px|frameless ]]
@@ Line 404: / Line 407: @@
 | [[file:C01548.01 200mu0012.jpg |75px|frameless ]]
 | [[file:C01548.01 300mu0011.jpg |75px|frameless ]]
-|
+|-
+|colspan="15"|
 {| {{table}}
 | align="center" style="background:#f0f0f0;"|'''Trench width'''
@@ Line 437: / Line 441: @@
 |}
 |-
-| January 2013
+|rowspan="2"| January 2013
-| Travka10, AZ 5214, '''10% open'''
+|rowspan="2"| Travka10, AZ 5214, '''10% open'''
-| Process A 55 cycles or 10:05 minutes, '''C01548.02'''
+|rowspan="2"| Process A 55 cycles or 10:05 minutes, '''C01548.02'''
 |[[file:C01548.02 2mu  0001.jpg |75px|frameless ]]
 |[[file:C01548.02 3mu  0002.jpg |75px|frameless ]]
@@ Line 455: / Line 459: @@
 |[[file:C01548.02 200mu 0136.jpg |75px|frameless ]]
 |[[file:C01548.02 300mu 0138.jpg |75px|frameless ]]
-|
+|-
+|colspan="15"|
 {| {{table}}
 | align="center" style="background:#f0f0f0;"|'''Trench width (µm)'''
@@ Line 488: / Line 493: @@
 |}
 |-
-| January 2013
+|rowspan="2"| January 2013
-| Travka20, AZ 5214, '''20% open'''
+|rowspan="2"| Travka20, AZ 5214, '''20% open'''
-| Process A 55 cycles or 10:05 minutes, '''C01548.03'''
+|rowspan="2"| Process A 55 cycles or 10:05 minutes, '''C01548.03'''
 | [[file:C01548.03 002mu0041.jpg |75px|frameless ]]
 | [[file:C01548.03 003mu0040.jpg |75px|frameless ]]
@@ Line 506: / Line 511: @@
 | [[file:C01548.03 200mu0028.jpg |75px|frameless ]]
 | [[file:C01548.03 300mu0027.jpg |75px|frameless ]]
-|
+|-
+|colspan="15"|
 {| {{table}}
 | align="center" style="background:#f0f0f0;"|'''Trench width (µm)'''
@@ Line 539: / Line 545: @@
 |}
 |-
-| January 2013
+|rowspan="2"| January 2013
-| Travka35, AZ 5214, '''35% open'''
+|rowspan="2"| Travka35, AZ 5214, '''35% open'''
-| Process A 55 cycles or 10:05 minutes, '''C01548.04'''
+|rowspan="2"| Process A 55 cycles or 10:05 minutes, '''C01548.04'''
 | [[file:C01548.04 002mu 0042.jpg |75px|frameless ]]
 | [[file:C01548.04 003mu 0043.jpg |75px|frameless ]]
@@ Line 557: / Line 563: @@
 | [[file:C01548.04 200mu 0056.jpg |75px|frameless ]]
 | [[file:C01548.04 300mu 0057.jpg |75px|frameless ]]
-|
+|-
+|colspan="15"|
 {| {{table}}
 | align="center" style="background:#f0f0f0;"|'''Trench width (µm)'''
@@ Line 590: / Line 597: @@
 |}
 |-
-| January 2013
+|rowspan="2"| January 2013
-| Travka50, AZ 5214, '''50% open'''
+|rowspan="2"| Travka50, AZ 5214, '''50% open'''
-| Process A 55 cycles or 10:05 minutes, '''C01548.05'''
+|rowspan="2"| Process A 55 cycles or 10:05 minutes, '''C01548.05'''
 |
 | [[file:C01548.05 003mu 0058.jpg |75px|frameless ]]
@@ Line 608: / Line 615: @@
 | [[file:C01548.05 200mu 0069.jpg |75px|frameless ]]
 | [[file:C01548.05 300mu 0070.jpg |75px|frameless ]]
-|
+|-
+|colspan="15"|
 {| {{table}}
 | align="center" style="background:#f0f0f0;"|'''Trench width (µm)'''
@@ Line 642: / Line 650: @@
 |}
@@ Line 657: / Line 662: @@
 ! width="50" rowspan="2"| Process Information
 ! colspan="15"| SEM images of trenches
-! rowspan="2" | Numbers
 |-
 ! 2 µm
@@ Line 675: / Line 679: @@
 ! 300 µm
 |-
-| January 2013
+|rowspan="2"| January 2013
-| Travka05, 600 nm oxide, '''5% open'''
+|rowspan="2"| Travka05, 600 nm oxide, '''5% open'''
-| Process A 110 cycles or 20:10 minutes, '''C01549.01'''
+|rowspan="2"| Process A 110 cycles or 20:10 minutes, '''C01549.01'''
 | [[file:C01549.01 002mu 0129.jpg |75px|frameless ]]
 | [[file:C01549.01 004-3mu 0128.jpg |75px|frameless ]]
@@ Line 693: / Line 697: @@
 | [[file:C01549.01 200mu 0118.jpg |75px|frameless ]]
 | [[file:C01549.01 300mu 0117.jpg |75px|frameless ]]
-|
+|-
+|colspan="15"|
 {| {{table}}
 | align="center" style="background:#f0f0f0;"|'''Trench width (µm)'''
@@ Line 726: / Line 731: @@
 |}
 |-
-| January 2013
+|rowspan="2"| January 2013
-| Travka10, 600 nm oxide, '''10% open'''
+|rowspan="2"| Travka10, 600 nm oxide, '''10% open'''
-| Process A 110 cycles or 20:10 minutes, '''C01549.02'''
+|rowspan="2"| Process A 110 cycles or 20:10 minutes, '''C01549.02'''
 | [[file:C01549.02 002mu 0085.jpg |75px|frameless ]]
 | [[file:C01549.02 003mu 0084.jpg |75px|frameless ]]
@@ Line 744: / Line 749: @@
 | [[file:C01549.02 200mu 0072.jpg |75px|frameless ]]
 | [[file:C01549.02 300mu 0071.jpg |75px|frameless ]]
-|
+|-
+|colspan="15"|
 {| {{table}}
 | align="center" style="background:#f0f0f0;"|'''Trench width (µm)'''
@@ Line 777: / Line 783: @@
 |}
 |-
-| January 2013
+|rowspan="2"| January 2013
-| Travka20, 600 nm oxide, '''20% open'''
+|rowspan="2"| Travka20, 600 nm oxide, '''20% open'''
-| Process A 110 cycles or 20:10 minutes, '''C01549.03'''
+|rowspan="2"| Process A 110 cycles or 20:10 minutes, '''C01549.03'''
 | [[file:C01549.03 002mu 0087.jpg |75px|frameless ]]
 | [[file:C01549.03 003mu 0088.jpg |75px|frameless ]]
@@ Line 795: / Line 801: @@
 | [[file:C01549.03 200mu 0100.jpg |75px|frameless ]]
 | [[file:C01549.03 300mu 0101.jpg |75px|frameless ]]
-|
+|-
+|colspan="15"|
 {| {{table}}
 | align="center" style="background:#f0f0f0;"|'''Trench width (µm)'''
@@ Line 828: / Line 835: @@
 |}
 |-
-| January 2013
+|rowspan="2"| January 2013
-| Travka35, 600 nm oxide, '''35% open'''
+|rowspan="2"| Travka35, 600 nm oxide, '''35% open'''
-| Process A 110 cycles or 20:10 minutes, '''C01549.04'''
+|rowspan="2"| Process A 110 cycles or 20:10 minutes, '''C01549.04'''
 | [[file:C01549.04 003mu 0115.jpg |75px|frameless ]]
 | [[file:C01549.04 003mu 0116.jpg |75px|frameless ]]
@@ Line 846: / Line 853: @@
 | [[file:C01549.04 200mu 0103.jpg |75px|frameless ]]
 | [[file:C01549.04 300mu 0102.jpg |75px|frameless ]]
-|
+|-
+|colspan="15"|
 {| {{table}}
 | align="center" style="background:#f0f0f0;"|'''Trench width (µm)'''