NEW-TYPE OF CHARGED-PARTICLES DETECTOR BASED ON POINT CONTACTS FORMEDIN A GAAS-ALGAAS HETEROSTRUCTURE BY SPLIT-GATES

We propose a new principle for a low temperature semiconductor detecto r of charged particles with possibly submicron lateral resolution base d on point contacts formed in the 2-dimensional electron gas (2DEG) of a G4As-AlxGa1-xAs heterostructure using split-gates. The detector ope rates up to liquid nitrogen temperatures. Impinging particles excite l ocally extra donors in the doping layer of the heterostructure. By mea suring simultaneous increase in the conductances of 3 point contacts d ue to the impacts of charged particles the position of penetration is calculated using the Thomas-Fermi approximation for screening in 2DEG.