FABRICATION OF N-CHANNEL AND P-CHANNEL IN-PLANE-GATE TRANSISTORS FROMSI SIGE/GE HETEROSTRUCTURES BY FOCUSED LASER-BEAM WRITING/

Focused laser beam writing is applied for thermally activated diffusio n of dopants into strained Si/Ge modulation-doped heterostructures. La teral p- and n-type potential barriers of sub-mu m width are achieved by local diffusion of boron and antimony into n- and p-type heterostru ctures, respectively. The potential modulation is determined from the temperature dependence of the thermionic current over the barrier. The se npn and pnp structures can be used to fabricate in-plane-gate trans istors which show transistor action up to room temperature. (C) 1996 A merican Institute of Physics.