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Tetra System

Tetra System

page created/edited by AMG July 2021

updated AMG Sept 2021

System Design

Diagram

File:Tetra-diagram.png

Components

Component

Description

To Do

Component

Description

To Do

UV Source

Quark Technology Excimer UV Irradiation System (QEF-35ST-ICTU) outputs at 172nm (5mW/cm2).

design optics

Hoffman Box

Hoffman box inherited from Dr. Paul Ho containing mass flow controllers and bubbler connections. All lines from box were gutted and replaced. Quarter-turn and pneumatic valves were kept and reused in line. N2 source in box is located in the RPCVD lab under the work bench on the wall. Wear your cleanroom hood when entering to change pressure in line.

 

Deposition Chamber

Cylindrical chamber inherited from Dr. Paul Ho. Contains a homemade substrate heater adapted for our application and a functioning Pirani gauge.

Terry - proper leak check

Mass Flow Controller

MKS-1179A mass flow controller inherited from Dr. Paul Ho is controlled by Lincoln SR5 Controller from Bravo N2 Plasma system with a homemade female to male Dsub15 cable.

add 1/4 turn between purge and source so we have have overflow

Substrate Heater

Homemade in-vacuum substrate heater from Dr. Paul Ho on a stainless steel stand powered by lab's standard EuroTherm/Sorenson setup through in-vacuum TC power connections.

install in-vacuum connections, treat wires and ring terminals

Stainless Steel Bubbler

A Sigma Aldrich stainless steel bubbler (###) has a 100mL capacity and is used to transition TEOS from a liquid to a gas for deposition.

Install VCR cap, load TEOS

Water Heating Bath

Lab-line heating bath coupled with a PCSensor USB thermometer (need to download program to operate) is used to heat stainless steel bubbler to desired temperature for operation.

 

Pneumatic Valves

Located at N2 input to mass flow controller and at exit of bubbler. Modulated by general N2 regulator on wall behind deposition chamber.

Replace upper valve with manual quarter-turn

Roughing Manifold

Connected to the deposition chamber via a Viton valve and to a UHP N2 line via a quarter-turn valve and is fitted with a safety exhaust line. Pressure is measured by an analog gauge.

 

Rotary Vane Wet Pump

An Agilent DS 202 Rotary Vane wet pump is utilized due to its ability to handle vapors. A general N2 line supplies inert gas to the gas ballast port to avoid oil contamination and reactions with atmospheric gases. Fashioned with oil trap to prevent back flow of oil into chamber. HOWEVER DESPITE PRECAUTIONS, PARTS THAT CONNECT TO CHAMBER AND INPUT/OUTPUT OF PUMP SHOULD NOT BE PUT ON OTHER VACUUM SYSTEMS.

install purge line adapter

Safety Exhaust Line

In case of loss of vacuum and/or overpressure of system a check valve is installed on the roughing manifold. The check valve opens when pressure reaches 25 psi and is attached to the pump exhaust.

 

UV Source Cooling

N2 cooling (15L/min, max 0.2 MPa) is supplied to UV source during operation via general N2 regulator shared by pneumatic valves and water cooling (3L/min, max 0.3 MPa) is supplied by CFT-75 recirculating chiller. Chiller recirculates a 50% water/50% ethylene glycol solution to meet UV source specifications.

Connect water and test

Standard Procedures

Loading Bubbler with TEOS

  1. Confirm that bubbler inlet/outlet are closed and that pneumatic valves to system are closed.

  2. Install disposable glovebag around bubbler to create a Nitrogen environment and leak check.

  3. Load glovebag with tools.

    1. Ultra-clean stainless steel funnel

    2. Standard and/or adjustable wrenches

    3. Gloves

    4. VCR gaskets

    5. Ultra-clean tweezers or VCR gasket holder

  4. Open VCR fill port.

  5. Use funnel to transfer TEOS from glass bottle to bubbler.

  6. Close fill port.

  7. Remove and dispose of glovebag.

Pumping Down

  1. Close quarter-turn valve to N2 and tighten down door.

  2. Turn on pump and open [insert name] valve.

  3. Pump-purge 3 times and proceed to SiO2 deposition procedure if sample is loaded.

Venting

  1. Let bubbler come to room temperature if venting post-operation of system.

  2. Close bubbler inlet valve and then bubbler output valve.

  3. Open quarter-turn valve connecting inlet and outlet lines in Hoffman box.

  4. Purge lines and chamber for 15 minutes.

  5. Close pneumatic valves and check that chamber has returned to roughly base pressure.

  6. Close [insert name] valve to wet pump and turn off pump.

  7. Unscrew door handle to avoid pressurizing the system.

  8. Flow N2 through the quarter-turn valve to come up to atmosphere.

SiO2 Deposition

section under construction, everything currently out of order

  1. Load sample and pump down system.

  2. Confirm that pneumatic valves are closed and all valves in Hoffman box are closed.

  3. Begin heating up water bath while monitoring with PCSensor USB.

  1. Open quarter-turn valve between bubbler input/output

  2.  

  3. Turn on recirculating chiller and set flow to 3L/min. Check that temperature is in 20-25C (?) range.

  4. Set general N2 regulator to [XX] psi. Pneumatic valves should also open when N2 is turned on.

  5. Warm up UV source.

  1. When bath reaches desired temperature open bubbler output valve and then the bubbler input valve.

  1. Set flow using mass flow controller. Monitor pressure to ensure that pressure reaches an equilibrium.

Subaccount-83 Purchasing

Tetra equipment tag number is 816758

See Purchasing wiki page for more information on how to purchase under -83 subaccount.

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