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ThermcoNitride

Silicon nitride (or nitride or Si3N4) is deposited at moderately high temperatures (~800C) and low pressure (~250 mtorr), using dichlorosilane (SiCl2H2) and ammonia (NH3). This furnace handles wafer up to 6 inch.

Operating Procedures (Quicksheet)

 

A.                 Check tube status

1.      Press Do key until Main Menu is reached.

2.      Use arrow keys to highlight Status Menu then press Return.

3.      Use arrows keys to highlight Tube Status then press Return.

4.      Type in Tube ID (4 for ThermcoNitride), then press Return.

5.      System should be running STBYNIT;  in prochold; temperature 525c

 

B.                  Vent tube

1.      Press START (STBYNITrecipe ends when boat is out)

2.      Load your wafers.

 

C.                 Load Recipe

1.      Enable Tube.

2.      Press STOP button until tube is in standby.

3.      Press Do key until Main Menu is reached.

4.      Use arrow keys to highlight Recipe Menu then press Return.

5.      Use arrows keys to highlight Compile Recipe then press Return.

6.      Type in Recipe Name (N2, LSN, LSNTEST), then press Return.

7.      For Recipe Name #2, press Return.

8.      For Parameter Table, press Return.

9.      Use arrow keys to highlight Download Only then press Return.

10.   Type in Tube ID (4 for ThermcoNitride), then press Return.

11.   Recipe parameter is time.

12.   Type  Delay Time (in the HH:MM:SS format) then press Return.

       (Thermco will flash orange Recipe Compile Succeeded once recipe is loaded.)

D.                 Run Program

1.      Press START to initiate recipe, after 10 seconds press START a second time to initiate the tube close.

2.      Monitor and log the lowest base pressure, the highest leak back pressure and the pressure during deposition.

3.      Wait for tube to process wafers. After deposition, the tube will ramp down to 525c and hold until you press START.  The tube will vent and open (~17 min).

4.      Unload your wafers after they have cooled several minutes.

5.      Press STOP button until tube is in standby.

6.      Compile the STBYNIT recipe.

7.      Press START to initiate tube close.

8.      STBYNIT will leakcheck tube and the stop in the process hold steo.

9.      Disable tube.

10.   Mute tube.

 E.                 If Leak Check Fails

1.      Put tube in standby.

2.      Compile NITYOUT recipe.

3.      Press START.  The recipe will reset temperature, backfill and then boat out.

 

                   

Process Monitoring and Machine Qualification

Nitride2 qualification results

LSNTEST qualification results

Purpose:

To provide a standard procedure to monitor Nitride thickness and uniformity both wafer-to-wafer and within-a-wafer.

 

Frequency:

To be completed after major maintenance such as a tube change or on a set schedule to be determined or as needed based on user feedback.

 

Documentation:

Test results are recorded on Coral.

 

Procedure:

First week of each month:

  1. Use four new 'L' test wafers; <100>, P-type (boron), 10-20 ohm-cm.

  2. Clean at wb-clean1/2 in the following sequence;  5:1:1 DI:H2O2:NH4OH ten minutes, rinse, 5:1:1 DI;HCl:H2O2 ten minutes, rinse, 50:1 DI:HF 30 sec, rinse, spin dry.

  3. Load program LSNTEST into Thermconitride furnace.  Time variable is 01:15:00.

  4. Load wafers into boats using clean (non-teflon) tweezers or vacuum wand.  Load wafers with the major flat up into the boats in the following positions:

1st boat: (Front closest to tube door), 20 empty slots,

1st  two dummies, (slots 21 & 22)

1st boat:  two test wafers (slot 23 & 24),

1st boat: one dummy. (slot 25)

2nd boat: one dummy, (slot 1)

2nd boat: two test wafers (slot 2 &3),

2nd boat one dummy,  21 empty slots.

LPCVD Test wafers

 

Third week of each month:

  1. Use four new 'L' test wafers; <100>, P-type (boron), 10-20 ohm-cm.

  2. Clean at wb-clean1/2 in the following sequence;  5:1:1 DI:H2O2:NH4OH ten minutes, rinse, 5:1:1 DI;HCl:H2O2 ten minutes, rinse, 50:1 DI:HF 30 sec, rinse, spin dry.

  3. Load program nitride2 into Thermconitride furnace.  Time variable is 00:30:00.

  4. Load wafers into boats using very clean (non-teflon) tweezers or vacuum wand.  Load wafers with the major flat up into the boats in the same positions as described in the above procedure for the LSNTEST qualification run.

 

 

 

Measure:

1. Measure the thickness and index of refraction at 9 points across the wafer using woollam using STS PECVD Nitride Qual

 

2.  Report the average thickness, standard deviation, and n at 633nm for the wafer on Badger

 

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