Patent ID: 6163163
Filing Date: 2000-12-19
Classification: H01L

Abstract:
A method of determining the doping concentration profile of a specimen of semiconductor material, the method comprising:a. providing a pair of electrodes,b. positioning the specimen between the pair of electrodes, the specimen being disposed on one of said electrodes and spaced from said other electrode by a nonconducting medium,c. applying a variable DC bias voltage between the pair of electrodes, the variable bias voltage varying between that corresponding to accumulation and that corresponding to depletion for the specimen,d. the rate at which the DC bias voltage varies being such that any inversion layer formed at the surface of the specimen is kept to a minimum and the period of variation being small compared to the amount of time required to charge or discharge the surface states associated with an unknown surface,e. providing a signal corresponding to the DC bias voltage,f. providing a signal corresponding to the total capacitance between the two electrodes during the DC bias voltage sweep,g. providing information corresponding to the area of the electrode spaced from the specimen,h. determining the capacitance of the nonconductive medium using the total capacitance signal,i. determining the depletion width using the total capacitance, the capacitance of the nonconducting medium and the area of the electrode spaced from the specimen information, andj. determining the doping concentration profile using the depletion width, the total capacitance, the DC bias voltage, and the area of the electrode spaced from the specimen information.