摘要 |
A floating body germanium (Ge) phototransistor with a photo absorption threshold bias region, and an associated fabrication process are presented. The method includes: providing a p-doped Silicon (Si) substrate; selectively forming an insulator layer overlying a first surface of the Si substrate; forming an epitaxial Ge layer overlying the insulator layer; forming a channel region in the Ge layer; forming a gate dielectric, gate electrode, and gate spacers; forming source/drain (S/D) regions in the Ge layer; and, forming a photo absorption threshold bias region in the Ge layer, adjacent the channel region. In one aspect, the second S/D region has a length, longer than the first S/D length. The photo absorption threshold bias region underlies the second S/D region. Alternately, the second S/D region is separated from the channel by an offset, and the photo absorption threshold bias region is the offset in the Ge layer, after a light p-doping.
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