1. Trench 3 process flow Discretes and MultiMarket ICs DMI – BL Power 17 july 2002

2. Semiconductors Owner: Ray Grover / page:2 DMI – BL Power Company Confidential Field ox 0.85um DP photo (1) to define p+ ring used in edge termination DP drive in oxidising ambient - field ox increases to 1.1um OD photo (2) opens window for active area Screen ox 55nm Trench photo (3) CD 0.5um stripe pattern Etch screen ox and Si to form trenches 1.6um deep, 0.8um wide with pitch of 4um Active area shown

3. Semiconductors Owner: Ray Grover / page:3 DMI – BL Power Company Confidential Round ox 85nm dry O2 Spray etch to remove round ox Gate ox 38nm 1100 dry O2/N2 Poly dep 0.8um POCl3 dope Phosphorus anneal Active area shown

4. Semiconductors Owner: Ray Grover / page:4 DMI – BL Power Company Confidential PS photo (4) and etch poly Etch gate oxide Screen ox 55nm AP photo (5) in centre of each stripe CD 0.75um AP implant through resist window and through screen ox Active area shown

5. Semiconductors Owner: Ray Grover / page:5 DMI – BL Power Company Confidential Strip resist p-body implant at 180keV pbody anneal 40 mins 1100 Active area shown

6. Semiconductors Owner: Ray Grover / page:6 DMI – BL Power Company Confidential SN photo (6) CD 1.2um Implant arsenic 120keV Active area shown

7. Semiconductors Owner: Ray Grover / page:7 DMI – BL Power Company Confidential Active area shown strip resist TEOS dep 0.6um (phos doped) Source anneal (densifies TEOS) CO photo (7) CD 1.8um dry etch CO window Sputter 5um AlSi

8. Semiconductors Owner: Ray Grover / page:8 DMI – BL Power Company Confidential Active area shown IN photo (8) gravel etch alloy 450 in H2 (some types have plasma nitride 1.0um and CB photo (9) and a second alloy) back grind and etch to 240um Back evap TiNiAg 0.55um total

9. Semiconductors Owner: Ray Grover / page:9 DMI – BL Power Company Confidential Trench Generation 3 SEM cross section

10. Semiconductors Owner: Ray Grover / page:10 DMI – BL Power Company Confidential Trench3 edge termination peripheral gate bus bar poly (drain connected) edge of active area poly field plate DP diffusion