Tempress S4T2 - PSG 4"

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Tempress S4T2 - PSG 4"
Equipment Details
Technology LPCVD
Materials Restriction CMOS Clean
Sample Size 100mm
Gases Used N2, O2, SiH4, 15% PH3/SiH4
Equipment Manual
Overview System Overview
Operating Procedure SOP
Supported Processes PSG
Maintenance Maintenance

The Tempress diffusion system is a modular horizontal furnace designed to process silicon wafers as part of the manufacturing technology of semiconductor, optical, MEMS, and solar devices. PSG (phosphorous silicate glass) is formed by using a process called LPCVD, Low Pressure Chemical Vapor Deposition. Chemical vapor deposition forms thin films on the surface of a substrate by thermal decomposition and/or reaction of gaseous compounds. The desired material is deposited directly from the gas phase onto the surface of the wafer. PSG is achieved by adding a small amount of the dopant gas PH3 (Phosphine) to the deposition gas, Silane. The important factors are gas ratio, temperature, and pressure.


  • The tool is down with communication issues, and is no longer actively supported. If you need to run this tool please create a helpdesk ticket.


  • PSG
  • Maximum Thickness - 2µm

System overview

Hardware details

  • N2 - Maximum flow 1 slpm
  • N2 - Maximum flow 10 slpm
  • O2 - Maximum flow 500 sccm
  • SiH4 - Maximum flow 100 sccm
  • 15% PH3/SiH4 - Maximum flow 200 sccm

Substrate requirements

  • Silicon only
  • Can process up to 25, 100 mm (4") wafers
  • Wafer thickness, ~525um for 100mm (4")
All samples must go through the RCA Pre-Furnace clean procedure before being processed in the furnace

Material restrictions

The Tempress S4T2 - PSG 4" is designated as a CMOS Clean class tool. Below is a list of approved materials for the tool. Approved means the material is allowed in the tool under normal circumstances. If a material is not listed, please create a helpdesk ticket or email info@lnf.umich.edu for any material requests or questions.

Supported processes

Process details

Characterization data

Standard operating procedure

Checkout procedure

  1. Create a Help desk Ticket requesting training.
  2. A process engineer will schedule a time for initial training. After completing training the user can attempt a checkout session. It may be necessary for some users to participate in more than one training session, prior to attempting check out.
  3. Schedule a checkout session with a tool engineer via the Help desk Ticket system. If this checkout is successful, the engineer will authorize you on the tool.


  • Maintenance is performed on the tool, after 20µm of accumulated deposition.
  • Maintenance consists of replacing the following quartz parts within the tube.
    • Cage
    • Twin rods
    • Bridge for twin rods
    • Thermocouple sheath
    • 5% PH3/SiH4 injector
    • Dummy wafers
  • Tube is replaced at 100µm of accumulated deposition.