Specific Process Knowledge/Thin film deposition/Furnace LPCVD TEOS: Difference between revisions

Revision as of 14:19, 26 July 2012

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LPCVD (Low Pressure Chemical Vapor Deposition) TEOS

Danchip has one LPCVD TEOS furnace (installed in 1995). The furnace is a Tempress horizontal furnace. The process is a batch process, where TEOS can be deposited on up to 15 wafer at a time.

TEOS is a silicon dioxide based on tetraethoxysilane. The reactive gas is TEOS, and the deposition takes place at a temperature of 725 degrees Celsius. It is possible to anneal the TEOS layer to improve the electrical properties as well as chemical resistance.

The LPCVD TEOS has a excellent step coverage and is very good for trench filling. The film thickness is very uniform over the wafer.

To get information on how to operate the furnace please read the user manual which is uploaded to LabManager.

Process Knowledge

Please take a look at the process side for deposition of TEOS oxide: Deposition of TEOS using LPCVD

Overview of the performance of the LPCVD TEOS furnace and some process related parameters

Purpose		Deposition of TEOS - Silicon dioxide based on tetraethoxysilane
Performance	Film thickness	0 nm - 2000 nm
	Step coverage	Good
	Film quality	Dense film Few defects
Process parameter range	Process Temperature	725 ^oC
	Process pressure	190 mTorr
	Gas flows	TEOS: 50 sccm O $_{2}$ : 30 sccm
Substrates	Batch size	1-25 4" wafer per run Deposition on both sides of the substrate
Substrates	Substrate material allowed	Silicon wafers (only clean wafers) with layers of silicon oxide or silicon (oxy)nitride (RCA cleaned) from furnaces in stack A or B in cleanroom 2 Quartz wafers (RCA cleaned)

@@ Line 16: / Line 16: @@
 <br clear="all" />
-==Overview of the performance of LPCVD Silicon Nitride and some process related parameters==
+==Overview of the performance of the LPCVD TEOS furnace and some process related parameters==
 {| border="2" cellspacing="0" cellpadding="10"
 |-
 !style="background:silver; color:black;" align="left"|Purpose
-|style="background:LightGrey; color:black"|Deposition of TEOS silicon oxide
+|style="background:LightGrey; color:black"|
 |style="background:WhiteSmoke; color:black"|
-*Deposition of silicon oxide on silicon nitride
+Deposition of TEOS - Silicon dioxide based on tetraethoxysilane
-*Deposition of silicon oxide on structured surfaces, eg. to cover holes or sealing small cavities.
 |-
 !style="background:silver; color:black" align="left" valign="top" rowspan="3"|Performance
-|style="background:LightGrey; color:black"|Film thickness|
+|style="background:LightGrey; color:black"|Film thickness
 |style="background:WhiteSmoke; color:black"|
-*Si<sub>3</sub>N<sub>4</sub>:~50Å - ~3000Å
+*0 nm - 2000 nm
-*SRN: ~50Å - ~10000Å
 |-
 |style="background:LightGrey; color:black"|Step coverage
@@ Line 44: / Line 42: @@
 |style="background:LightGrey; color:black"|Process Temperature
 |style="background:WhiteSmoke; color:black"|
-*800-835 <sup>o</sup>C
+*725 <sup>o</sup>C
 |-
 |style="background:LightGrey; color:black"|Process pressure
 |style="background:WhiteSmoke; color:black"|
-*80-230 mTorr
+*190 mTorr
 |-
 |style="background:LightGrey; color:black"|Gas flows
 |style="background:WhiteSmoke; color:black"|
-*SiH<math>_2</math>Cl<math>_2</math>:10-100 sccm
+*TEOS: 50 sccm
-*NH<math>_3</math>:10-75 sccm
+*O<math>_2</math>: 30 sccm
 |-
 !style="background:silver; color:black" align="left" valign="top" rowspan="2"|Substrates
@@ Line 63: / Line 61: @@
 | style="background:LightGrey; color:black"|Substrate material allowed
 |style="background:WhiteSmoke; color:black"|
-*Silicon wafers (new from the box or RCA cleaned)
+*Silicon wafers (only clean wafers)
 **with layers of silicon oxide or silicon (oxy)nitride (RCA cleaned)
+**from furnaces in stack A or B in cleanroom 2
 *Quartz wafers (RCA cleaned)
 |-
 |}