Omnivision's patent application US20120319242 "Dopant implantation hardmask for forming doped isolation regions in image sensors" by Duli Mao, Hsin-Chih Tai, Vincent Venezia, Keh-Chiang Ku, Yin Qian, Gang Chen, Rongsheng Yang, Howard Rhodes talks about using hardmask for high-energy implants between PDs. The mentioned hardmask materials are silicon oxide and polysilicon. The application talks about openings of order of 0.2-0.4um with hardmask thickness of 2um, said to have enough stopping power for 1MeV boron implants (combined with photoresist).
I'm a little surprised to see that the application was filed only in June 2011; I thought Omnivision has been using hardmasks since much earlier than that.
Yes, I guess it is in TSMC.
ReplyDeleteBut now, the patent is for OV Wuhan-Foundry.