High-purity and high-quality 4H–SiC grown at high speed by chimney-type vertical hot-wall chemical vapor deposition

Abstract

4H-SiC layers have been homoepitaxially grown at a high growth rate of 25 m/h by chimney-type vertical hot-wall chemical vapor deposition at 1700°C. Through photoluminescence measurement, the intrinsic defect, so-called L 1 peak, was found to be reduced under a C-rich condition. In the deep level transient spectroscopy measurement, the Z 1 center was also found to be suppressed under a C-rich condition. For a 75-m-thick epilayer, the net donor concentration was reduced to as low as 5ϫ10 12 cm Ϫ3. In low-temperature photoluminescence, free exciton peaks are dominant, indicating high purity of the epilayer.

Effects of C/Si ratio in fast epitaxial growth of 4H–SiC(0 0 0 1) by vertical hot-wall chemical vapor deposition

“…Although high-quality 4H-SiC epitaxial growth has been realized in several CVD reactors [3][4][5] problems remain to be solved for the growth of thick epilayers; for example, the typical growth rate in SiC CVD has been 2-10 mm/h. A few attempts of fast epitaxial growth ranging from 10 to 25 mm/h at high temperature in several vertical hot-wall reactors have been demonstrated [6][7][8]. In order to fabricate high-voltage bipolar devices, not only high growth rate but also low impurity concentration and long carrier lifetime are required.…”

Electronic Structure of Deep Defects in SiC

“…Based on this dependence a model of a complex between N and C I or V Si has been suggested for the Z 1,2 defect. Fujihira et al [137] studied the defect in layers grown with the C/Si of 0.6, 0.7 and 0.8 and found the Z 1 concentration in the low 10 13 cm −3 range in one layer with the N concentration ∼ 1 × 10 16 cm −3 . The center was suggested to be an intrinsic complex involving a Si antisite or C vacancy [137].…”

Phonon-Assisted Tunneling from Z 1/Z 2 in 4H-SiC

“…Z 1 /Z 2 defects have been extensively studied using deep-level transient spectroscopy (DLTS). [1][2][3][4][5][6][7][8][9] The most prominent feature of the DLTS spectrum of electron-irradiated 4H-SiC samples is the Z 1 /Z 2 center located at about 0.7 eV below the conduction band. The prominent peak is due to two-electron emission from both Z 1 and Z 2 defects.…”