2. Anelva
Sputter
PECVD
DRIE

3. Dry Etch– Tool status Update Feb 2014
DRIE
Load lock O-Ring changed . Ordered for new set.
Wafer transport issue – robot arm aligned.
Process: scallop smoothening trials in progress
DRIE deep etches with S-Type wafer – scallops
FGA show no effect
Scallop etch in RIE
SEM imaging and process tuning in progress
RIE
Scallops smoothening
Combined process with DRIE.
using Anisotropic Si etch (RIE) smoothening scallops.
Result – scallop reduced to 145nm from 1.3 µm.
Trials for deeper etch and scallop size to be done.
SiO2 plastering
Trench filling by PECVD SiO2 , followed by RIE SiO2 etch.
Work in progress for better conformal deposition.
Reduced scallop
SiO2 plastering
PECVD
vacuum leak in load lock –VAT valve to arrive tomorrow!
Process is done in manual mode

4. Technical Note

6. Sheet resistance (Ω/□)
E-Beam Evaporator.
Issues faced:
Turbo pump error(WARNING F097):
There was a bug in the software which controls the turbo pump. This issue was fixed by upgrading the software. It took 24 hours to fix the issue, as the data cable which is used to communicate between a computer and the turbo pump was in Hyderabad (PFEIFFER office). We have requested the PFEIFFERs’ Engineer to keep the cable in Bangalore office, so that we can cut down the tools’ down time.
The old graphite crucible which was used to evaporate Al material broke and we were unable to evaporate Al using the new 25 cc graphite crucible. However we are now able to evaporate Al in copper crucible. In feature we will be working on optimization of Al evaporation with the new graphite crucible.
Below table contains the optical and electrical characteristics of ITO thin films:
TRIAL
Thickness (nm)
Sheet resistance (Ω/□)
Transmission %
Before annealing
After annealing 1
200
570
215 4 61 2 80
> 800 K
30.5 25 51 3
395
413 77 86
297 91 93 5
525
398 98 97 6
247
194 96 7
160
128
121 92