NONDESTRUCTIVE METHOD FOR DETECTION OF MOBILITY OF CHARGE CARRIER IN SEMICONDUCTOR STRUCTURES USING HALF-INSULATING SUBSTRATES AND DEVICE WHICH IMPLEMENTS SAID METHOD

摘要

FIELD: semiconductor instruments for scientific investigations and for testing quality of materials which are used in manufacturing of semiconductor instruments. SUBSTANCE: method involves generation of nondestructive contacts to structure. Contact which is located on side of half- insulating substrate is liquid and transparent to microwaves, for example, it is made from ethyl alcohol. Contact which is located on side of conducting layer is designed as pressed point-wise metal one. Constant back bias voltage V_st, is applied to n-i junction between film and half-insulating substrate (buffer layer). Said bias voltage V~st, changes width of depletion layer of n-i junction. Width of n-i junction is modulated by alternating bias voltage V_st+V~st. This results in possibility to modulate conductance of depletion layer of n-i junction alternating constituent in measured reflected microwave power is detected and its magnetic-field dependency is used for detection of mobility as function of reverse bias voltage which is applied to n-i junction, using equation , where ΔP_mn is alternating constituent of reflected microwave power; μ(V_st) is mobility as function of reverse bias voltage V_st;, B is magnetic field intensity. In addition invention describes device which implements said method. This invention provides possibility to run nondestructive analysis of mobility profile near border between active and buffer layers and detect mobility of inner layers of multiple-layer semiconductor structures. This results in possibility of optimization of technology for development of such structures and to test quality of such structures during later stages of manufacturing. EFFECT: increased precision of mobility detection and increased functional capabilities due to measuring mobility and mobility profile (dependency of mobility on reverse bias level) in inner layers of semiconductor structures, in particular, structures which have high- conductance contact n+ layer.