PROCESS DESCRIPTION
P
ROCESS
M
ANUAL
4.3-8
116
Gas O2 [2] at 0 [SCCM] Variable Command: No
117
Gas SIH4 [3] at 0.0 [SCCM] Variable Command: No
118
Gas PRESSURE [8] at 0 [MTOR] Variable Command: No
119
Digital out N2 PURGE[9] = ON,N2PROCES[10] = ON,PROCESS[11] =
ON,EVACSIH4[12] = OFF,,,SOFTSTRT[15] = ON,MAINVAC[16] = OFF
Variable Command: No
120
Alarm on digital in PRESS N2[1] = ON,PRESSAIR[2] = ON,doorclsd[3] =
ON,VACFAIL[4] = OFF,,,TEMP SCR[7] = ON,EXCESS[8] = ON
121
Abort recipe 08
122
20 BACKFILL 2
123
Message BACKFILL [14]. Sonalert alarm No
124
Time: 000:10:00 (hr:min:sec) Variable Command: No
125
Gas N2 [1] at 10.00 [SLM] Variable Command: No
126
Digital out N2 PURGE[9] = ON,N2PROCES[10] = ON,PROCESS[11] =
ON,EVACSIH4[12] = OFF,,,SOFTSTRT[15] = OFF,MAINVAC[16] = OFF
Variable Command: No
127
END
4.3.8
Troubleshooting an LTO process
Problem: Cause:
Solution:
Wafers are thick at the door side
and thin at the pump side.
•
Temperature ramp is not
correct.
•
Injector design is not optimal
•
Insufficient N
2
carrier gas
•
Increase temperature ramp
(door side temperature lower
then pump side temperature).
•
Use different injector design
•
Increase N
2
carrier gas
Wafers are thick at the pump side
and thin at the door side.
•
Temperature ramp is not
correct.
•
Injector design is not optimal
•
Too much N
2
carrier gas
•
Reduce temperature ramp
(door side temperature higher
then pump side temperature).
•
Use different injector design
•
Reduce N
2
carrier gas
Wafers are thick at the top and
thin at the bottom.
•
Wafers are not aligned
parallel.
•
Place wafers parallel and flat
side at the top
Wafers are thick at the edges and
thin at the center.
•
Wafers are placed too close
together
•
Cage design is not optimal
•
Place wafers further apart
•
Use different cage design
No consistency in uniformity.
•
Dirty quartz ware or wafers.
•
No constant pressure control.
•
Draft along the furnace.
•
Clean tube, quartz ware and
paddle.
•
Use clean wafers.
•
Check pressure control.
•
Close possible draft holes.
Layer is too thin cross load.
•
Deposition time is too short.
•
Increase deposition time in
recipe.
Layer is too thick cross load
•
Deposition time is too long.
•
Decrease deposition time in
recipe.
