NONDESTRUCTIVE METHOD AND DEVICE FOR DETERMINING MOBILITY OF CHANGE CARRIERS IN SEMICONDUCTOR STRUCTURES ON HALF-INSULATING SUBSTRATES Russian patent published in 1997 - IPC

FIELD: semiconductor engineering; nondestructive inspection of semiconductor materials. SUBSTANCE: this nondestructive microwave measurement method involves formation of nondestructive contacts for structure: liquid one, transparent for microwave radiation on half-insulating substrate side and hold-down contact on conducting layer side. Applied to n-i film-to-half-insulating structure transition through these contacts is DC reverse bias voltage V_sub which changes width of n-i transition packing area and thickness of n-i transition is modulated by applying through these contacts ac bias voltage V~sub

, thereby modulating layer conductance on end of packing area of n-i transition; V_sub+V~sub sum does not exceed breakdown voltage of n-i transition. Separated from reflected microwave power being measured is ac component whose magnetic-field dependence is used to determine mobility as function of reverse bias voltage applied to n-i transition using equation ΔP_mw(B,V_sub)=ΔP_mw(B=0,V_sub)/[I + (μ(V_sub)B)²],, where ΔP_mw is ac component of reflected microwave power; μ(V_sub) is mobility as function of reverse bias voltage V_sub; B is magnetic flux density. EFFECT: facilitated procedure, improved accuracy. 2 cl, 3 dwg