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

← Older edit

VisualWikitext

Latest revision as of 09:31, 6 February 2024

Feedback to this page: click here

Unless otherwise stated, this page is written by DTU Nanolab internal

6" LPCVD nitride furnace (E3) located in cleanroom E-6

Deposition of Silicon Nitride using LPCVD

DTU Nanolab has two LPCVD (Low Pressure Chemical Vapour Deposition) furnaces for deposition of silicon nitride:

A 4" furnace (installed in 1995) for deposition og stoichiometric nitride on 4 inch wafers.
A 6" furnace (installed in 2008) for deposition of low stress/silicon rich nitride on 4 inch and 6 inch wafers. Deposition of stoichiometric nitride on 4 inch wafers is also allowed in this furnace.

In LabManager the two furnaces are named "Furnace: LPCVD nitride (4") (B2)" and "Furnace: LPCVD nitride (6") (E3)", respectively. Both furnaces are Tempress horizontal furnaces.

Please check the cross contamination information in LabManager before you use any of the two furnaces.

The LPCVD silicon nitride deposition is a batch process, where nitride can be deposited on a batch of up to 15 wafers (in the 4" nitride furnace) or 25 wafers (in the 6" nitride furnace) at a time. The deposition takes place under vacuum (120-200 mTorr, depending on the process) and at high temperature (780-845 C, depending on the process). The reactive gases are ammonia (NH₃) and dichlorsilane (SiH₂Cl₂).

The LPCVD nitride has a very good step coverage, and the film thickness is very uniform over the wafers.

The user manuals, quality control procedures and results, user APVs, technical information and contact information can be found in LabManager:

4" LPCVD nitride furnace (B2)

6" LPCVD nitride furnace (E3)

Furnace computer manual

Manual for the furnace computer to the A, B, C and E stack furnaces

The A, B, C and E stack furnaces can be controlled either from a touch screen by each furnace or from a furnace computer. The user manual for the furnace computer can be found here:

Manual for furnace computers for the A, B, C and E stack furnaces

Process information

Using LPCVD silicon nitride as a masking material for KOH etching

Equipment performance and process related parameters

Equipment		6" LPCVD nitride furnace (E3)	4" LPCVD nitride furnace (B2)
Purpose	Deposition of	Silicon rich (low stress) nitride Stoichiometric nitride	Stoichiometric nitride
Performance	Step coverage	Very good	Very good
Performance	Film quality	Deposition on both sides of the substrate Dense film Few defects	Deposition on both sides of the substrate Dense film Very few defects
Process parameter range	Temperature	810-845 ^oC The temperature vary over the furnace tube	780-790 ^oC The temperature vary over the furnace tube
	Pressure	150 mTorr	200 mTorr
	Gas flows	For Low stress nitride Dichlorsilane (SiH₂Cl₂): 200 sccm Ammonia (NH₃): 50 sccm For Stoichiometric nitride on 6" wafers Dichlorsilane (SiH₂Cl₂): 45 sccm Ammonia (NH₃): 180 sccm	Dichlorsilane (SiH₂Cl₂): 20 sccm Ammonia (NH₃): 80 sccm The gas flows depend on whether nitride is deposited on 4" or 6" wafers
Substrates	Batch size	1-25 100 mm wafers 1-25 150 mm wafers Including a test wafer	1-15 100 mm wafers Including a test wafer
	Allowed materials	Silicon wafers (new or RCA cleaned) with layers of silicon oxide or silicon (oxy)nitride from the A, B and E stack furnaces Quartz/fused silica wafers (RCA cleaned)	Silicon wafers (new or RCA cleaned) with layers of silicon oxide or silicon (oxy)nitride from the A, B and E stack furnaces Quartz/fused silica wafers (RCA cleaned)

Rules for storage and RCA cleaning of wafers to the B2 and E3 furnaces

Storage and cleaning of wafer to the B2 and E3 furnaces

@@ Line 1: / Line 1: @@
-'''Feedback to this page''': '''[mailto:labadviser@danchip.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.danchip.dtu.dk/index.php/Specific_Process_Knowledge/Thin_film_deposition/Furnace_LPCVD_Nitride click here]'''
+'''Feedback to this page''': '''[mailto:labadviser@nanolab.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.nanolab.dtu.dk/index.php/Specific_Process_Knowledge/Thin_film_deposition/Furnace_LPCVD_Nitride click here]'''
+<i> Unless otherwise stated, this page is written by <b>DTU Nanolab internal</b></i>
 [[Category: Equipment|Thin film F]]
@@ Line 11: / Line 13: @@
 ==Deposition of Silicon Nitride using LPCVD==
-Danchip has two LPCVD (Low Pressure Chemical Vapour Deposition) furnaces <!--[[Specific Process Knowledge/Thin film deposition/B2 Furnace LPCVD Nitride|LPCVD furnaces]]--> for deposition of silicon nitride:
+DTU Nanolab has two LPCVD (Low Pressure Chemical Vapour Deposition) furnaces <!--[[Specific Process Knowledge/Thin film deposition/B2 Furnace LPCVD Nitride|LPCVD furnaces]]--> for deposition of silicon nitride:
 *A 4" furnace (installed in 1995) for deposition og stoichiometric nitride on 4 inch wafers.
 *A 6" furnace (installed in 2008) for deposition of low stress/silicon rich nitride on 4 inch and 6 inch wafers. Deposition of stoichiometric nitride on 4 inch wafers is also allowed in this furnace.
@@ Line 21: / Line 23: @@
 The LPCVD nitride has a very good step coverage, and the film thickness is very uniform over the wafers.
 '''The user manuals, quality control procedures and results, user APVs, technical information and contact information can be found in LabManager:'''
-[http://labmanager.danchip.dtu.dk/function.php?module=Machine&view=view&mach=84 4" LPCVD nitride furnace (B2)],
+[http://labmanager.dtu.dk/function.php?module=Machine&view=view&mach=84 4" LPCVD nitride furnace (B2)]
+[http://labmanager.dtu.dk/function.php?module=Machine&view=view&mach=250 6" LPCVD nitride furnace (E3)]
+[https://labmanager.dtu.dk/d4Show.php?id=1926 Furnace computer manual]
+== Manual for the furnace computer to the A, B, C and E stack furnaces ==
+The A, B, C and E stack furnaces can be controlled either from a touch screen by each furnace or from a furnace computer. The user manual for the furnace computer can be found here:
-[http://labmanager.danchip.dtu.dk/function.php?module=Machine&view=view&mach=250 6" LPCVD nitride furnace (E3)]
+[[media:Furnace_computer_manual.pdf|Manual for furnace computers for the A, B, C and E stack furnaces]]
@@ Line 38: / Line 50: @@
 == Process information ==
-*[[/Deposition of low stress nitride using the 4" LPCVD nitride furnace|Deposition of low stress nitride using the 4" LPCVD nitride furnace <span style="color:Red">(No longer available to deposit low stress nitride by 4" LPCVD nitride furnace)</span>]]
 *[[/Deposition of stoichiometric nitride using the 4" LPCVD nitride furnace|Deposition of stoichiometric nitride using the 4" LPCVD nitride furnace]]
-*[[/Deposition of stoichiometric nitride using the 6" LPCVD nitride furnace|Deposition of stoichiometric nitride using the 6" LPCVD nitride furnace <span style="color:Red">(Only available for 6" wafers and special permission required)</span>]]
+*[[/Deposition of low stress nitride using the 4" LPCVD nitride furnace|Deposition of low stress nitride using the 4" LPCVD nitride furnace <span style="color:Red">(Low stress nitride depositions are no longer available in this furnace - use the 6" nitride furnace instead)</span>]]
 *[[/Deposition of low stress nitride using the 6" LPCVD nitride furnace|Deposition of low stress nitride using the 6" LPCVD nitride furnace ]]
+*[[/Deposition of stoichiometric nitride using the 6" LPCVD nitride furnace|Deposition of stoichiometric nitride using the 6" LPCVD nitride furnace <span style="color:Red">(4" wafers need a special permission using as a back up of 4" LPCVD nitride furnace, B2)</span>]]
 *[[/Using LPCVD silicon nitride as a masking material for KOH etching|Using LPCVD silicon nitride as a masking material for KOH etching]]
@@ Line 133: / Line 147: @@
 <!--hide text
 ==Using LPCVD silicon nitride as a masking material for KOH etching==
-At Danchip stoichiometric silicon nitride is mainly used as masking material for potassium hydroxide (KOH) etching. The etch rate of the nitride in 80 <sup>o</sup>C KOH is expected to be less than 1 Å/min.
+Stoichiometric silicon nitride is mainly used as masking material for potassium hydroxide (KOH) etching. The etch rate of the nitride in 80 <sup>o</sup>C KOH is expected to be less than 1 Å/min.
 There are regularly users having problems with pinholes in the silicon nitride after KOH etching. It is not always clear what the reasons are, but we suspect problems can arise due to
@@ Line 143: / Line 157: @@
 '''To avoid too many or too large particles in the nitride'''<br\>
 *If possible, use the new nitride furnace to deposit stoichiometric nitride. In order to avoid problems with particles it is not allowed to deposit low stress nitride in this furnace, and the particles level is therefore low compared to the older nitride furnace.
-*Before running a process keep in close contact with the Danchip staff (especially the process specialist on the furnace) or take a look at the logbook to make sure that the nitride furnace is expected to be in a good state.
+*Before running a process keep in close contact with the Nanolab staff (especially the process specialist on the furnace) or take a look at the logbook to make sure that the nitride furnace is expected to be in a good state.
 '''To avoid too rough handling of the wafers after the nitride deposition'''<br\>
@@ Line 153: / Line 167: @@
 *It is recommended to have a of silicon oxide layer between the silicon substrate and the nitride layer to reduce the stress level between the layers. The silicon nitride is then expected to have less tendency to break.
 hide text-->
+== Rules for storage and RCA cleaning of wafers to the B2 and E3 furnaces ==
+*[[Specific_Process_Knowledge/Thermal_Process/Storage_and_cleaning_of_wafer_to_the_A,_B,_C_and_E_stack_furnaces|Storage and cleaning of wafer to the B2 and E3 furnaces]]