SiC-Elektronik. Teilprojekt: Untersuchungen zur Metallisierung Abschlussbericht

SiC is a promising wide bandgap semiconductor material for active electronic devices. An important problem is the formation of low resistance ohmic contacts, especially for p-type SiC. The deposition of all known metals onto p-type SiC will always result in a depletion p-type contact. We developed a model for p-depletion contact to SiC. Only 1% of the introduced acceptors are ionised at room temperature. To increase the amount of acceptors a very shallow p-dopant implantation were performed. Another aim of this research was to study the structural and chemical changes of the surface, as well as the interface and bulk after implantation, annealing and contact formation. We performed complex solid state analysis involving Atomic Force Microscopy (AFM), Reflection of High Energy Electron Diffraction (RHEED), Transmission Electron Microscopy (TEM) and Rutherford Backscattering (RBS). The contact resistance was measured at rectangular and circular structures using the transmission line method. It is obvious that the contact behaviour becomes ohmic with the Al/Ti metallisation. WSi_2 metallisation created a non ohmic contact behaviour before and after contact annealing, only at higher operating temperatures an ohmic character is found. Specific contact resistance of 5*10"-"4 #OMEGA#cm"2 was achieved on p-implanted 6H-SiC with Al/Ti metallisation. (orig.)SIGLEAvailable from TIB Hannover: F97B2338+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman