Anelva Sputter PECVD DRIE

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 anneals @1000DegC 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

Technical Note

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