Fabrication of n- and p-channel in-plane-gate transistors from Si/SiGe/Ge heterostructures by focused laser beam writing

Focused laser beam writing is applied for thermally activated diffusion of dopants into strained Si/Ge modulation-doped heterostructures. Lateral p- and n-type potential barriers of sub-μm width are achieved by local diffusion of boron and antimony into n- and p-type heterostructures, respectively. The potential modulation is determined from the temperature dependence of the thermionic current over the barrier. These npn and pnp structures can be used to fabricate in-plane-gate transistors which show transistor action up to room temperature.