Study of PbTe, PbSnTe, PbSe, PbSnSe, and Ge metal insulator semiconductor (MIS) structures

A thorough understanding and a well developed fabrication procedure of MIS structures are the prerequisite for CCD applications. The object of this thesis is to study the narrow gap semiconductor MIS and investigate its feasibility for IR-CCI applications. Two MIS studies were made. First, MIS of five lead-tin semiconductors were fabricated using E-gun evaporated 100-450A thick Al(2)0(3) or Si0(2) layers as insulators. C-V measurements indicated that these MIS behave qualitatively like that of Si-MOS. Accumulation, depletion and inversion layers were controlled by the gate voltage. However, comparisons of measured C-V with theoretical calculations did not yield quantitative agreement. Second, MIS of 0.05D-cm p-type and 40D-cm n-type Ge were also studied. C-V and C-t measurements indicated standard MOS behavior although some small hysteresis was found. Analysis based on C-V data showed that the flatband voltage was approximately -1.2 volts and interface state density was on the order of 10(13) /cm(2). In addition, effects of electron bombardment simulating the space environment around Jupiter on a n-channel depletion MOSFET were studied. The negative threshold voltage was de­ creased and at a total dose of 2Xl0(15) e/cm(2), it became positive making the MOSFET an enhancement type of very poor quality.http://archive.org/details/studyofpbtepbsnt1094516830Lieutenant, United States NavyApproved for public release; distribution is unlimited