Title :
Improved stability in PbS/Al2O3 thin-film transistors
Author_Institution :
Aerojet ElectroSystems Co., Azusa, CA, USA
Abstract :
Insulated-gate field-effect-transistor structures , prepared with thin films of lead sulfide as the semiconductor and aluminum oxide as the gate insulator, exhibit greatly improved stability with regard to carrier-trapping effects as compared with other thin-film transistors (TFTs) such as those made of cadmium selenide. The devices are prepared in a series of additive evaporation steps (through stencil masks) in a single pumpdown of the vacuum system. They are n-type but exhibit field-effect inversion to p-type. They are generally enhancement devices but can also be prepared as depletion devices by increasing the time and temperature of the postdeposition anneal. The carrier mobility is of the order of 10 cm2/V-sec, and the carrier concentration is approximately 3 × 1017/cm3.
Keywords :
II-VI semiconductors; IV-VI semiconductors; annealing; cadmium compounds; carrier density; carrier mobility; electron traps; hole traps; insulated gate field effect transistors; lead compounds; masks; semiconductor thin films; stability; thin film transistors; vacuum deposition; PbS-Al2O3; TFT; additive evaporation steps; aluminum oxide; cadmium selenide; carrier concentration; carrier mobility; carrier-trapping effects; depletion devices; enhancement devices; field-effect inversion; gate insulator; insulated-gate field-effect-transistor structures; lead sulfide; postdeposition anneal; single pumpdown; stability; stencil masks; thin films; thin-film transistors; vacuum system; Dielectrics; Epitaxial growth; Fabrication; Lead; Silicon; Vacuum systems;
Conference_Titel :
Electron Devices Meeting (IEDM), 1974 International
Conference_Location :
Washington, DC
DOI :
10.1109/IEDM.1974.6219814