Oxford ICP Etcher - Process Control Data
Process Control Data - InP Ridge Etch (Oxford ICP Etcher)
|InP Ridge Etch: 60°C, 3mT, 800W/65W, Cl2=18, H2=15, CH4=10sccm, time=5min00sec (300sec)
Sample Size: 2” unpatterned InP wafer “dummy” pieces, surrounding 1x1cm patterned sample, ~30-40% SiO2 masking (NingC's pattern). Silicon carrier, no adhesive.
Seasoning: 10min “Std Clean - O2/SF6 Chamber Clean 20C (Edit Time)”, then load 2” “dummy” unpatterned InP wafer pieces on Si carrier (rough side up) and run 5min of “Std InP Ridge Etch - Cl2/CH4/H2 60C”
Sample Prep: Prior to dry etching, the sample is submerged in NH4OH : DI = 1:10 (3mL:30mL) for 1 min, then DI rinsed and N2 dried.
|Date||Sample#||Etch Rate (nm/min)||Etch Selectivity (InP/SiO2)||Comments||SEM Images|
|9/30/22||ND_60c_093022||310||21.1||High etch rate and selectivity||[30D] [CS]|
|9/2/22||ND_60c_090622||246||7.5||Very low etch rate and selectivity||[30D] [CS]|
|9/1/22||ND_60c_090122||268||9.4||Low Etch rate/selectivity, could be due to recent Cl2 clean||[45D] [CS]|
|7/1/22||ND_60c_070122||294||11.9||Did not dip in NH4OH||[45D] [CS]|
|5/19/22||DJ_60c_007||326||TBA||After chamber vented, cleaned (wet + dry). Forgot NH4OH wet-etch before dry etch. ER and profile look nominal.||[45°1],[45°2] [XS]|
|4/27/22||NP_60c_008||320||9.2||directly after chamber clean. Identical results to before chamber clean. Chamber appeared clean when opened.||[45°] [XS]|
|4/26/22||NP_60c_007||312||9.93||day before chamber clean||[45°] [XS]|
|4/19/22||NP_60c_006||330||9.53||Chamber opened and brown gunk observed in chamber right after the etch was done. Etch rate unaffected.||[45°] [XS]|
|4/13/22||NP_60c_005||320||11.51||New mask pattern with long lines to cleave through.||[45°] [XS]|
|↑ Changed mask pattern going forward (~50% open area), apparent etch rate changes due to measuring different features.|
|3/30/22||NP_60c_004||427||11.17||*etched for 3min*
~30-40% SiO2 masking (NingC's pattern)
|1/26/22||NP_1_26_003||452||12.9||~30-40% SiO2 masking (NingC's pattern)||[45°] [XS]|
Etch Rate Dependence on Sample Size (Oxford ICP Etcher)
We have found that the size of the InP piece loaded (no adhesive, onto Silicon carrier wafer) affects the etch rate, but does not affect the etch profile - ie. etches are still smooth and vertical, but rate varies with sample area.
|InP Ridge Etch: 60°C, 3mT, 800W/65W, Cl2=18, H2=15, CH4=10sccm, time=5min05sec (305sec)
Silicon carrier, no adhesive.
|Date||Sample#||Sample Size (dimensions, mm)||Sample Size (area, mm2)||Etch Rate (nm/min)||Etch Selectivity (InP/SiO2)||Comments||SEM Images|
|1/11/22||DJ_InPRidge||4.5 x 2.5||11.25||602||64.6nm left||~50% SiO2 masking (GCA Calibration pattern)|||
|1/12/22||DJ_InPRidge||4.5 x 3||13.5||563||76.4nm left||~50% SiO2 masking (GCA Calibration pattern)|||
|1/12/22||DJ_InP#3||4.5 x 3||13.5||612||71nm left||~50% SiO2 masking (GCA Calibration pattern)|||
|1/26/22||NP_?||10 x 10||100||400-450||~250nm left||~30-40% SiO2 masking (NingC's pattern)|
|1/26/22||NP_?||1/4 of 50mm wafer||490||378||276nm left||~30-40% SiO2 masking (NingC's pattern)|||