SOI grating definition
From OptoelectronicsWiki
Contents
Current Processes
Sweeper Vertical Grating Coupler Process
Pre-clean: Remove native oxide and/or dielectric hardmask HF dip Ebeam PR spin coat (2:1 ZEP) ACE,ISO,DI PEII - O2 Descum (100W, 300mTorr, 60sec) Dehydration Bake (150C, 5min) N2 Gun (1min) Cools and cleans wafer Spin 2:1 ZEP (3000rpm, 30sec) - Recipe 5 ~225nm, Use a filtered syringe Pre-Exposure Bake (180C, 4min) Cover hotplate top to prevent additional particulate Thermal Au Evaporation Evaporate 11nm Au Ebeam Writing Conditions 4th Lens Dose 350uC/cm2 (Please be aware this is pitch dependent, but has shown good results over a range of pitches if the substrate is not highly doped) Development Remove Au in wet Au etchant 10s DI Rinse N2 Dry 1:1 MIBK:ISO Development - 60s Use a fresh batch 9:1 MIBK:ISO Rinse - 15s DO NOT RINSE WITH DI N2 Dry DO NOT RINSE WITH DI Grating Etch AFM etch depth calibration recommended Single Step Bosch Etch Process - JTB_GR Rates: ~170nm/min w/o Sanovac 5 ~141nm/min w/ Sanovac 5
Process Development Summary
Dose/Duty Cycle Analysis with Proximity Effect Observations
File:2010-03-01 Grating Update.pptx
File:2010-12-07 Grating Update.pptx
Future Untested Processes
Sweeper Two Etch Depth Grating Process (INCOMPLETE)
Standard Process Pre-clean: Remove native oxide and/or dielectric hardmask HF dip Ebeam PR spin coat (2:1 ZEP) ACE,ISO,DI PEII - O2 Descum (100W, 300mTorr, 60sec) Dehydration Bake (150C, 5min) N2 Gun (1min) Cools and cleans wafer Spin 2:1 ZEP (3000rpm, 30sec) - Recipe 5 ~225nm, Use a filtered syringe Pre-Exposure Bake (180C, 4min) Cover hotplate top to prevent additional particulate Thermal Au Evaporation Evaporate 11nm Au Ebeam Writing Conditions 4th Lens Dose 350uC/cm2 (Please be aware this is pitch dependent, but has shown good results over a range of pitches if the substrate is not highly doped) Development Remove Au in wet Au etchant 10s DI Rinse N2 Dry 1:1 MIBK:ISO Development - 60s Use a fresh batch 9:1 MIBK:ISO Rinse - 15s DO NOT RINSE WITH DI N2 Dry DO NOT RINSE WITH DI Add PR protection layer Spin AZ4210 (4000rpm, 30sec) Pre-Exposure Bake (95C, 1min) Lithography - Pattern a window in the deep etch region Litho Tool: GCA Stepper / Autostepper Exposure: 3sec / 1sec (NEEDS CALIBRATION) Focus Offset: 0 (NEEDS CALIBRATION) NO POST-EXPOSURE BAKE Develop (AZ400K 1:4 diluted, 1min) DI Rinse Grating Partial Etch - Etch the difference in depths (deep target - shallow target) AFM etch depth calibration recommended Single step Bosch etch process - JTB_GR Rates: ~170nm/min w/o Sanovac 5, ~141nm/min w/ Sanovac 5 Strip PR protection layer Strip AZ4210 in ISO - Should not attack ZEP(2:1) Grating Shallow/Finish Deep Etch - Etch the difference in depths (deep target - shallow target) AFM etch depth calibration recommended Single step Bosch etch process - JTB_GR Rates: ~170nm/min w/o Sanovac 5, ~141nm/min w/ Sanovac 5