EXOEMISSION AND PHASE-TRANSITIONS ON REAL CRYSTAL AND POROUS SILICON SURFACES

The thermally stimulated (T=20-400 degrees C) ''spontaneous'' electron and ion emission (exoemission) from crystal and porous silicon surfac es was investigated. The exoemission current bursts, observed from an etched silicon surface and from a porous silicon surface as a result o f cooling, are attributed to exothermal crystallization of a thin oxid e layer on a ''real'' silicon surface. The exoemission bursts due td h eating during repeated heat-cycle tests are attributed to diverse stru ctural phase transitions in the tridymite and crystobalite modificatio ns in a thin oxide layer. The results obtained for a real silicon surf ace are compared to the emission current bursts from a surface oxide l ayer obtained by oxidation of silicon at high temperature. (C) 1996 Am erican Institute of Physics.