K.X. Liu

Publications (2)1.47 Total impact

• Article: Imaging Surface Pits and Dislocations in 4H-SiC by Forescattered Electron Detection and Photoluminescence

  Y.N. Picard, K.X. Liu, R.E. Stahlbush, M.E. Twigg
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  ABSTRACT: Forescattered electron detection (FED) was utilized to image surface depressions resulting from threading screw and edge dislocations Forescattered electron detection (FED) was utilized to image surface depressions resulting from threading screw and edge dislocations in 4H-SiC epitaxial layers. These surface depressions, or growth pits, exhibited two morphology types. Screw and edge dislocations in 4H-SiC epitaxial layers. These surface depressions, or growth pits, exhibited two morphology types. Screw and edge dislocations could be imaged by photoluminescence and differentiated by their interactions with propagating partial dislocations (PDs). could be imaged by photoluminescence and differentiated by their interactions with propagating partial dislocations (PDs). Correlations between FED and photoluminescence showed that sharp-apex pits 1μm in size and strip-shaped pits 500nm in size could be linked to individual screw and edge dislocations, respectively. Forescattered Correlations between FED and photoluminescence showed that sharp-apex pits 1μm in size and strip-shaped pits 500nm in size could be linked to individual screw and edge dislocations, respectively. Forescattered electron detection demonstrated sufficient sensitivity to image surface features previously resolvable only by atomic force electron detection demonstrated sufficient sensitivity to image surface features previously resolvable only by atomic force microscopy. This new technique is nondestructive, noncontact, and capable of rapid, spatial mapping of growth pits resulting microscopy. This new technique is nondestructive, noncontact, and capable of rapid, spatial mapping of growth pits resulting from threading screw and edge dislocations in SiC epitaxial layers. from threading screw and edge dislocations in SiC epitaxial layers.
  Journal of Electronic Materials 05/2012; 37(5):655-661. · 1.47 Impact Factor
• Conference Proceeding: Effects of Dislocations and Stacking Faults on the Reliability of 4H-SiC PiN Diodes

  R.E. Stahlbush, K.X. Liu, M.E. Twigg
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  ABSTRACT: Silicon carbide has numerous advantages for fabricating power devices compared to silicon including a 3X larger bandgap, higher internal breakdown field and higher thermal conductivity. However, there are a number of material and processing problems that must be overcome before SiC devices are reliable and commercially viable. A major material problem impeding the development of reliable PiN diodes is the formation of stacking faults during forward-biased operation, which causes the forward voltage to drift upward. The origin of the stacking faults, how they affect the electrical behavior and progress in reducing stacking faults are discussed
  Reliability Physics Symposium Proceedings, 2006. 44th Annual., IEEE International; 04/2006