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Epi2 (Chamber A)

Epitaxial reactor for reduced pressure epitaxial deposition of Ge, high concentration silicon germanium (Ge above 15%) with a wide range of doping concentrations and hydrogen anneals.
Short summary of tool capabilities.

Picture and Location



 Epi2 is the the first chamber on the tool and is referred to as Chamber A in most Epi communications.


Process Capabilities

Cleanliness Standard

  •  Clean


Performance of the Tool

What the Tool CAN do

  • Deposit Doped and undoped Ge, SiGe (Ge above 15%), and H2 anneals.
  • Layers thicker than three microns in multiple depositions.


What the Tool CANNOT do

  • Layer thicker than 3 microns in a single deposition.
  • Wafer pieces.
  • Silicon depositions
  • High concentration SiGe (Ge below 15%)
  • Doping above 1E18 (B2H6 or PH3)


Available Gases

Gas Maximum Flow Concentration
purge H2 80 SLM 100%
purge N2 80 SLM  100%
deposition SiH4 100 SCCM  100%
deposition GeH4 28 SCCM  100%
deposition SiClH4 500 SCCM  100%
dopant B2H6 500 SCCM 1% (balance H2)
dopant B2H6 500 SCCM 100 PPM (balance H2)
dopant PH3 500 SCCM 1% (balance H2)
dopant AsH3 500 SCCM 100 PPM (balance H2)


Contact List and How to Become a User

Contact List

The following people make up the Tool Quality Circle:

  • Process Staff: Maurice
  • Maintenance: Ted
  • Super-Users:  Ed Fei and Ju Hyung Nam


Training to Become a Tool User

Please follow the following procedure to become a qualified user of Epi2;

Read all material on the SNF website concerning the tool, including Background, Process Capabilities, Operating Procedures and Process Monitoring. 

  1. Contact a superuser (link to superusers list) or qualified user of the furnace to arrange to ‘shadow’ them while they use the tool.  The reservation option on coral will show who will be using the tool in the near future.  You are responsible to be with that labmember for the full time they are operating the tool, and it would be intelligent to ask questions and try to become as familiar as possible with the furnace during this ‘shadowing.’  You may have to shadow the superuser or qualified user more than one time.
  2. The labmember you choose to follow will have a Shadow Checklist (see below) for the furnace and you will have to be able to understand each point on it before the labmember notifies the staff responsible for training that you are ready for training.  Both of you must agree that you are ready.  You may have to shadow a labmember more than once.  Fill out the Shadowing form with the labmember.
  3. Contact the staff trainer to arrange for training on the furnace.
  4. If there is a written test for the tool you will need to hand it in to the staff member before training commences.
  5. After training you will be given  provisional qualification status.  This allows you to use the furnace during staffed hours, 0600-1800 Mon-Fri only.
  6. Once a superuser or staff member has watched you and you have satisfactory demonstrated the proper use the tool you will be granted a full qualification to use the tool anytime, 24/7.


Shadow Checklist

  • Trained at WB Diff.
  • Aware of the cleanliness level Epi.
  • Familiar with basic equipment description.
  • Know max thickness allowed per deposition.
  • Know which etch recipe to run and frequency.
  • Know how to correctly load/unload wafers using vacuum wand and proper cleanliness tweezers (flat direction, slots).
  • Familiar with the function of each of the steps in a recipe.
  • Know how to modify and save a recipe.
  • Know how to assign recipes to loaded wafers.
  • Know how to run in automatic and manual.
  • Know how to fill out logbook.


Operating Procedures

  1. Log in on Coral
  2. System -> Login/Logout
  3. ChA -> Monitor process (to check status...should be in inert idle)
  4. ChA -> Command -> Cold Idle (60sec.)
  5. ChA -> Command -> Warm Idle (~370C)
  6. ChA -> Command -> Active Idle
  7. System -> Control System ->ETCHCOAT-CHA Run
  8. (Active Idle) -> System -> Controll system -> Manual
  9. Wafer -> Open LLA door -> <check status> Wafer -> Monitor wafer
  10. <Wafer loading> Wafer -> LOAD/UNLOAD LLA
  11. System -> Control System -> Automatic
  12. Program -> Recipe Directory -> <Check the recipe steps>
  13. System -> Control System -> <assign the recipe>
  14. Wafer -> Run (Go) button
  15. Wafer -> Monitor wafer
  16. Wafer -> Stop button
  17. System -> Control system -> Abort sequencer
  18. Wafer -> LOAD/UNLOAD LLA -> Open LLA door
  19. <Take out the wafer>
  20. Wafer -> Close LLA door
  21. Ch A -> Monitor chamber -> (Lower < 300C)
  22. ChA -> Command -> Inert Idle
  23. System -> Control System -> <Unload your recipe>
  24. System -> Login/Logout -> Log Out Current User
  25. Coral logout


Process Monitoring and Machine Qualification

Purpose: To provide a standard procedure to monitor epi thickness, intrinsic resistivity and uniformity.

Frequency of test: to be completed after major maintenance such as a tube change, susceptor change  or on a set schedule to be determined or as needed based on user feedback.

Documentation of results: to be posted in hardcopy in the Uniformity Test Book located in the lab and posted in the email archive for Epi2.


  1. Use one new 'L' test wafers; <100>, P-type (boron), 10-20 ohm-cm.
  2. Clean at wbdiff in the following sequence;  5:1:1 H2O:H2O2:NH4OH ten minutes, rinse, 5:1:1 DI;HCl:H2O2 ten minutes, rinse, 50:1 DI:HF 30 sec, rinse, spin dry.
  3. Measure wafer weight using the microbalance.
  5. Measure wafer weight using the microbalance.
  6. Calculate the epi thickness using the weight gain.
  7. Inspect wafer under UV light for haze. ( If haze is present system may require a bake out and another staff)
  8. Use Prometrix to measure epi resistivity across using program.  Record results on Coral.
  9. Save wafer in a box with the date.  It may be re-tested sometime in the future.


Epi Based Research Papers


Sidewall epitaxial piezoresistor process and characterisation for in-plane force sensing applications  A.A. Barlian 


Room temperature 1.6 μm electroluminescence from Ge light emitting diode on Si substrate   Szu-Lin Cheng

 Effects of hydrogen annealing on heteroepitaxial-Ge layers on Si: Surface roughness and electrical quality   Ammar Nayfeh

 Fabrication of High-Quality p-MOSFET in Ge Grown Heteroepitaxially on Si  Ammar Nayfeh


 Ge on Si by Novel Heteroepitaxy for High Efficiency Near Infrared Photodetection  Ali K. Okyay


High-efficiency metal–semiconductor–metal photodetectors on heteroepitaxially grown Ge on Si   Ali K. Okyay


Defect Reduction of Ge on Si by Selective Epitaxy and Hydrogen Annealing   Hyun-Yong Yu


Low-Temperature, Low Pressure CVD and Solid Phase Crystallization of Silicon–Germanium Films   Munehiro Tada


Effect of Isochronal Hydrogen Annealing on Surface Roughness and Threading Dislocation Density of Epitaxial Ge on Si  Shin-ichi Kobayashi


p-Channel Ge MOSFET by Selectively Heteroepitaxially Grown Ge on Si  Hyun-Yong Yu


Germanium In Situ Doped Epitaxial Growth on Si for High-Performance n+/p Junction Diode   Hyun-Yong Yu


High-Efficiency p-i-n Photodetectors on Selective-Area-Grown Ge for Monolithic Integration    Hyun-Yong Yu


High Performance n-MOSFETs with Novel Source/Drain on Selectively Grown Ge on Si for Monolithic Integration    Hyun-Yong Yu


Effect of isochronal hydrogen annealing on surface roughness and threading dislocation density of epitaxial Ge films grown on Si  Shin-ishi Kobayashia


Low Temperature Germanium Growth on Silicon Oxide Using Boron Seed Layer and In Situ Dopant Activation    Munehiro Tada





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