Basal plane slip and formation of mixed-tilt boundaries in sublimation-grown hexagonal polytype silicon carbide single crystals

Optical microscopy, synchrotron white beam x-ray topography (SWBXT), and high resolution x-ray diffraction (HRXRD) were used to study the distribution of basal plane dislocations in bulk 4H silicon carbide crystals grown by the physical vapor transport method. An etch pit array was observed on the silicon face of KOH-etched off-cut wafers. The arrays were aligned parallel to each other and perpendicular to the off-cut direction. The etch pits were oval-shaped, which is characteristic of basal plane dislocations. Corresponding array images have been observed by SWBXT. Based on the characteristic distribution, the etch pit arrays are interpreted as the slip traces of high temperature deformation during the growth process. Thermoelastic stress is proposed as the plausible cause of the deformation. In addition, basal plane dislocation pileups were found in the proximity of polygonized threading edge dislocation arrays. SWBXT and HRXRD were used to study the misorientation related to such dislocation structure...

[1]  K. Niihara.  Slip systems and plastic deformation of silicon carbide single crystals at high temperatures , 1979 .

[2]  K. Maeda,et al.  Dislocation glide motion in 6H SiC single crystals subjected to high-temperature deformation , 1987 .

[3]  R. Glass,et al.  Status of Large Diameter SiC Crystal Growth for Electronic and Optical Applications , 2000 .

[4]  J. Takahashi,et al.  Sublimation growth of SiC single crystalline ingots on faces perpendicular to the (0001) basal plane , 1994 .

[5]  M. Skowronski,et al.  Structure of recombination-induced stacking faults in high-voltage SiC p–n junctions , 2002 .

[6]  E. Janzén,et al.  Crystalline imperfections in 4H SiC grown with a seeded Lely method , 1994 .

[7]  G. Corman.  Creep of 6H α‐Silicon Carbide Single Crystals , 1992 .

[8]  M. Graef,et al.  Identification of prismatic slip bands in 4H SiC boules grown by physical vapor transport , 2000 .

[9]  H. Suematsu,et al.  Kinking and Cracking Caused by Slip in Single Crystals of Silicon Carbide , 1991 .

[10]  M. Graef,et al.  Origin of domain structure in hexagonal silicon carbide boules grown by the physical vapor transport method , 2000 .

[11]  H. Lendenmann,et al.  Crystal Defects as Source of Anomalous Forward Voltage Increase of 4H-SiC Diodes , 2001 .

[12]  E. Janzén,et al.  Structural macro-defects in 6H-SiC wafers , 1993 .

[13]  C. Carter,et al.  Kinetics and Mechanisms of High‐Temperature Creep in Silicon Carbide: I, Reaction‐Bonded , 1984 .

[14]  Katsuyuki Suzuki,et al.  Defects in plastically deformed 6H SiC single crystals studied by transmission electron microscopy , 1988 .

[15]  Robert F. Davis,et al.  Kinetics and Mechanisms of High-Temperature Creep in Silicon Carbide. II. Chemically Vapor Deposited, , 1984 .

[16]  Robert E. Reed-Hill,et al.  Physical Metallurgy Principles , 1972 .

[17]  N. Ohtani,et al.  Structural defects in α-SiC single crystals grown by the modified-Lely method , 1996 .

[18]  F. Durst,et al.  Global modeling of the SiC sublimation growth process: prediction of thermoelastic stress and control of growth conditions , 2001 .

[19]  V. D. Heydemann,et al.  Plastic Deformation and Residual Stresses in SiC Boules Grown by PVT , 2000 .

[20]  N. Ohtani,et al.  Structural properties of subgrain boundaries in bulk SiC crystals , 2000 .

[21]  M. Dudley,et al.  Partial dislocations in the X-ray topography of as-grown hexagonal silicon carbide crystals , 2001 .

[22]  A. G. Crocker,et al.  Introduction to dislocations, 3rd ed.: By D. Hull and D. J. Bacon. Pp. 257. Pergamon Press, Oxford. 1984. Hard cover £20.00, Flexicover £7.50 , 1985 .