HIGH-RESISTIVITY ZNSE COATED SUBSTRATES FOR MICROSTRIP GAS-CHAMBERS

Microstrip gas chambers (MSGCs) require substrates with sheet resistan ce in the range of 10(13)-10(16) ohms/square to eliminate polarization and surface charging effects between the electrodes. Thin films of II -VI semiconductors deposited on glass or plastic substrates are attrac tive for this application since bulk resistivity of these semiconducto rs vary in the range 10(9)-10(12) ohm-cm and films with good uniformit y can be deposited over large-areas using inexpensive deposition techn iques. In this paper, deposition, characterization, and fabrication of MSGCs using ZnSe thin films are reported for the first time. ZnSe thi n films were deposited on glass and plastic substrates by thermal evap oration. Sheet resistance of ZnSe varied in the range of 10(15) to 10( 16) ohms/square depending on the deposition conditions. A MSGC detecto r fabricated using a 0.5 mu m thick ZnSe layer on glass substrate exhi bited best values; gas gain of 25000 and an energy resolution of about 16.7% FWHM at a gain of 1080 for a Fe-55 source.