Detection of Yield-Impacting Defects in SiC and GaN Materials used in the Power Device Market. R. Sappey, M. Raghunathan, A. Somanchi, T.

Transcription

1 Detection of Yield-Impacting Defects in SiC and GaN Materials used in the Power Device Market R. Sappey, M. Raghunathan, A. Somanchi, T. Pierson

2 AGENDA Integrated surface & photoluminescence defect detection MOCVD chamber mapping for defectivity Epi process monitoring Defect traceability to device yield Yield impact of substrate defects

3 AGENDA Integrated surface & photoluminescence defect detection MOCVD chamber mapping for defectivity Epi process monitoring Defect traceability to device yield Yield impact of substrate defects

4 Defect Inspection for Power Device Market GaN-based epitaxy materials substrate SiC-based materials integrated PL Defect inspection tool designed for GaN epi process control and accelerated MOCVD ramp Sensitivity to nm-scale and buried CMP scratches on SiC substrates Integrated surface defect detection and photoluminescence for SiC defects MOCVD batch mapping hillocks micropits Basal Plane Dislocation map industry need: classify yield-limiting defects and optimize MOCVD pocket design industry need: detect substrate scratches that impact subsequent MOCVD growth industry need: full-wafer mapping of PL stacking faults, and BPDs at production throughputs 4 KLA-Tencor Confidential - Internal Use Only

5 Defect Photoluminescence (PL) SiC defects known to PL under UV excitation 5 KLA-Tencor Confidential

6 Defect Photoluminescence (PL) SiC defects known to PL under UV excitation PL bar stacking faults PL triangles 6 KLA-Tencor Confidential UV ScN Candela - PL

7 BPD Detection and Mapping top yield and reliability killer for bipolar transistor devices high-purity BPD classification BPD wafer map NUV PL NUV PL high-purity BPD classification NUV PL near-uv PL images 370nm 410nm contrast is reversed because 4H-SiC PL is reduced when BPD/TDs are present NUV PL 7 KT confidential

8 AGENDA Integrated surface & photoluminescence defect detection MOCVD chamber mapping for defectivity Epi process monitoring Defect traceability to device yield Yield impact of substrate defects

9 MOCVD Chamber Mapping for Defectivity clear defect trends observed across MOCVD chamber potential temperature gradient across MOCVD pockets hillocks micropits 9 KLA-Tencor Confidential - Internal Use Only

10 MOCVD Chamber Mapping for Defectivity clear defect trends observed across MOCVD chamber potential temperature gradient across MOCVD pockets Additional 20% electrical yield loss hillocks micropits 10 KLA-Tencor Confidential - Internal Use Only

11 MOCVD Chamber Mapping for Defectivity clear defect trends observed across MOCVD chamber potential temperature gradient across MOCVD pockets hillocks micropits 11 KLA-Tencor Confidential - Internal Use Only

12 AGENDA Integrated surface & photoluminescence defect detection MOCVD chamber mapping for defectivity Epi process monitoring Defect traceability to device yield Yield impact of substrate defects

13 PL Defects on SiC Substrates Grain boundary PL Bright Spot PL Dislocations substrate crystallographic defects captured with NUV-PL around periphery of boule doping signature 13

14 SiC Substrate and Epitaxy known yield-impacting defects substrate epitaxy epitaxy Defect Yield impact Yield impact Defect Yield impact particles low mid high low mid high step bunching low mid high stains MOCVD droplets topographic defects surface carrots surface scratches carrots (PL) buried CMP scratches bulk crystalline micropipes grain boundaries (PL) macropits micropits substrate only surface triangles triangles (PL) buried stacking faults (PL) bar stacking faults (PL) TED (NUV PL) BPD (NUV PL) #1 reliability killer for bipolar transistor device 14

15 Thank You! questions or inquiries please contact