Chapter 1.7

Material & Process Compatibility Policy

 

1.0        Title

Material & Process Compatibility Policy

2.0        Purpose

This document is designed to provide quick reference for material and compatibility policy in the Microlab and will be reviewed by staff with updated information on a regular basis. This information in addition to equipment manual chapters and should provide answer to some of the frequently asked questions about material and process compatibility in the Microlab. Microlab members are expected to contact staff for any questions that may not be clear in their mind and/or not covered by the pertinent equipment lab manual chapters, including this one.

3.0        Scope

This chapter defines furnace pre-clean, metal substrate/pyrex/borofloat glass restrictions in the Microlab. This is a quick reference and by no means encompasses all the issues and concerns that may be raised about MOS, Non-MOS and old lab process/operation. Microlab users should adhere to specific guidelines spelled out in the operation manuals in addition to the information provided here to make their final decision on "what is allowed" and "what is not allowed" in the Microlab. As always ask when in doubt. Process Engineering and/or technology manager should be consulted for any issues or concerns you may have regarding material and process compatibility, not covered in the lab manual chapters. Furthermore, any new chemical and material introduced in the Microlab must be reviewed by staff and Material Data Sheet (MSDS) form posted in the blue binders at the entrance of the Microlab.

4.0        Applicable Documents

Revision History

5.0        Definitions and Process Terminology

N/A

6.0        Safety

N/A

7.0        Statistical/Process Data

N/A

8.0        Available Process, Gases, Process Notes

Review specific equipment manual in addition to the policies outlined in Section 9.0.

9.0        Material & Process Policy (Cross-Contamination Prevention Measures)

9.1        VLSI / Furnace Restriction

No gold in any VLSI tools; no gold in the VLSI area including Bank 5 and Lam 3.  Certain metals are allowed in specific furnaces, as described below. If you do not see your metal described, discuss with staff before proceeding.

9.2        Basic Wafer Cleaning Policy (furnace pre-clean for silicon and 100% quartz (fused silica) wafers)

New wafers receive 1 piranha clean. Photoresist coated wafers need to have their PR stripped, then receive 2 piranha cleans (Non-MOS followed by MOS). Metal wafers (wafers with metal layer/s on them) should never be exposed to piranha, as it will attack the metal film and major contamination to the sink will occur.

     New 4" and 6" wafers must be cleaned in Sink 6 piranha prior to loading into an MOS or Non-MOS furnace.

     Resist coated 4" and 6" wafers with no metal layers on them, must be stripped with PRS3000 or O2 plasma, and then cleaned in Sink8 piranha followed by Sink6 piranha clean, prior to loading into a MOS or Non-MOS furnace.

9.3        Specialized Procedures for Furnace Processing of Metal-Coated Wafers

     Only specific metals are allowed in specific non-MOS furnaces.

     Do not attempt to clean any metal-coated wafers in any piranha.

     Metal wafers (wafers with metal layer/s) 4” & 6” wafers may be processed in specific non-MOS furnaces after being cleaned in the sink5 metal clean bath followed by dump rinse (QDR) and SRD steps at Sink5, as well.

     Resist coated 4" & 6" metal wafers (wafers with metal layer/s) may be processed in specific non-MOS furnaces after resist stripping with PRS3000 and/or O2 plasma, followed by cleaning in the sink5 metal clean bath, then dump rinse (QDR) and SRD steps also at Sink5.

     Non-MOS furnaces presently approved for processing of metal wafers (wafers with metal layer/s) are:

- Tystar4 for annealing

- Tystar16 for amorphous or poly silicon deposition

- Tystar17 for low stress nitride and HTO deposition

- Tystar18 for sintering process

- Tystar12 and tystar20 for LTO and poly-Ge/poly/SiGe film deposition, respectively.

9.4    Specialized Procedures for Furnace Processing of Non-Quartz Glass Wafers

Fo  For information on different types of non-quartz glass wafers, see Process Module 31.

     Non-quartz glass wafers should Never be cleaned at Sink6.

     New 4" and 6" non quartz glass wafers must be cleaned in Sink 8 piranha prior to loading into a Non-MOS furnace.

     Resist coated 4" and 6" non-quartz glass wafers must be stripped with PRS3000 or O2 plasma, and then cleaned in Sink8 piranha prior to loading into a Non-MOS furnace.

.

  4” & 6” non-quartz glass wafers are allowed in Tystar 4 (note most non-quartz glass wafers can not be exposed to temperatures >550 C) in Tystar20 (dep temp < 450 C)  and in Tystar16 (dep temp < 550 C) in a special boat (see Process staff).9.5    Special Restriction on Etch Equipment

     No metal etching is allowed in Lam1, Lam2, Lam4 and Lam 5. Use Lam3 (metal etcher) for metal etch process, only.

     No non-quartz glass wafer (e.g.,Pyrex or borofloat) etching is allowed in Lam4 and Lam5. Non-quartz glass wafers may be etched in P-therm. See Chapter 1.3, Process Module 31 for more information.

     Do not grow C4F8 based polymers thicker than 1 micron in STS.

     No metal hard masks are allowed in the STS. Oxide/nitride and photoresist etch masks only.

9.6    Additional Information

Tystar 20 has specifically been developed to enable deposition of poly-Ge and poly-SiGe films on top of completed CMOS wafers. Therefore, expected metal contaminants in Tystar 20 may include: Al, Al2%Si, Ti, W.

Furnace Pre-cleaning Requirement Table

Acceptable 4" and 6” substrates: Si, SOI, quartz

(Non-quartz glass wafers (pyrex/borofloat) in Tystar16, Tystar12, and Tystar20, only)

 

Pre-Cleaning Required for

 New Si,

SOI,

Quartz

 Wafers

 PR Coated Si,

SOI,

Quartz Wafers

New Non-Quartz Glass Wafers

PR Coated

Non-Quartz

Glass Wafers

Metal  (blank film)

PR Coated Metal Wafers

(See tube specific notes)

Equip.
Description

Tystar1

Atmos. Furnace (MOS)

Sink6

Restricted

See Tystar1 manual

NA

NA

NA

NA

Tystar2

Atmos.  Furnace (MOS)

Sink6

Wet Strip or Matrix +

Sink8 + Sink6

NA

NA

NA

NA

Tystar3

Atmos.  Furnace (Non-MOS)

Sink6

Wet Strip or Matrix +

Sink8 + Sink6

NA

NA

NA

NA

Tystar4

Atmos.  Furnace (Non-MOS)

Sink6

Wet Strip or Matrix +

Sink8 + Sink6

Sink8

Wet Strip or Matrix +

Sink8

Sink5 metal clean bath +

Sink5 QDR/SRD

*See Notes 1 and 2

Wet Strip or Matrix + Sink5 metal clean bath+

Sink5 QDR/SRD

*See Notes 1 and 2

Tylan5

Atmos.  Furnace (MOS)

Sink6

Restricted
see Tystar1 manual

NA

NA

NA

NA

Tylan6

Atmos.  Furnace (MOS)

Sink6

Restricted
see Tystar1 manual

NA

NA

NA

NA

Tylan7

Atmos.  Furnace (MOS)

Sink6

Wet Strip or Matrix +

Sink8 + Sink6

NA

NA

NA

NA

Tylan8

Atmos.  furnace (Non-MOS)

Sink6

Wet Strip or Matrix +

Sink8 + Sink6

NA

NA

NA

NA

Tystar9

LPCVD Furnace (MOS)

Sink6

Wet Strip or Matrix +

Sink8 + Sink6

NA

NA

NA

NA

Tystar10

LPCVD Furnace (MOS)

Sink6

Wet Strip or Matrix +

Sink8 + Sink6

NA

NA

NA

NA

Tystar11

LPCVD Furnace (MOS)

Sink6

Wet Strip or Matrix +

Sink8 + Sink6

NA

NA

NA

NA

Tystar12

LPCVD Furnace (Non-MOS)

Sink6

Wet Strip or Matrix +

Sink8 + Sink6

Sink8

Wet Strip or Matrix +

Sink8

Sink5 metal clean bath +

Sink5 QDR/SRD

*See Notes 1 and 2

Wet Strip or Matrix + Sink5 metal clean bath+

Sink5 QDR/SRD

*See Notes 1 and 2

Tystar13

Atmos.  Furnace (Non-MOS)

Sink6

Wet Strip or Matrix +