Effects of ion implantation process on defect distribution in SiC SJ-MOSFET

Abstract

A superjunction (SJ) structure in power devices is compatible with low specific on-resistance and high breakdown voltage. To fabricate the SJ structure in SiC power devices, the repetition of ion implantation and epitaxial growth processes is a practical method. However, the impact of ion implantation on device performance has rarely been reported. In this study, we measured the carrier lifetime distributions in a SiC MOSFET with an SJ structure using a microscopic free carrier absorption method. Furthermore, we observed the distribution of defects via cathodoluminescence and deep levels via deep-level transient spectroscopy. We observed that Al ion implantation induced defects and reduced the carrier lifetime in the SJ structure. However, N ion implantation does not significantly induce defects. Additionally, Al ion implantation at room temperature exhibited more significant effects than implantation at 500°C. The results can aid in controlling the carrier lifetime in SiC SJ MOSFETs.

Very High In‐Plane Magnetic Field Sensitivity in Ion‐Implanted 4H‐SiC PIN Diodes

“…This coincides with experimental observations of a high density of annealing persisting defects originating from aluminum implants in SiC. [44,45] Another effect is the large dependency of the observed hump and sensitivity on the overlap length of the oxide with the p+ region. The smaller the overlap, the smaller the hump and sensitivity (Figure 6).…”

“…Considering studies in literature concerning implant-induced defects, these assumptions are justified. [24][25][26][43][44][45] We note that although traps are known to be generated by both aluminum and nitrogen implants, their density can be considerably higher for aluminum implants due to the higher atomic mass of aluminum, thus creating more defects. [45] Due to their high thermal stability, implant-induced intrinsic defects can survive the high annealing temperatures, which annihilates many other extrinsic defects.…”

“…[24][25][26][43][44][45] We note that although traps are known to be generated by both aluminum and nitrogen implants, their density can be considerably higher for aluminum implants due to the higher atomic mass of aluminum, thus creating more defects. [45] Due to their high thermal stability, implant-induced intrinsic defects can survive the high annealing temperatures, which annihilates many other extrinsic defects. Also, they diffuse be-low the junction during the annealing and can in addition react forming new defects.…”

Effects of proton implantation for expansion of basal plane dislocations in SiC toward suppression of bipolar degradation: review and perspective

“…Thus far, we have focused on process-based techniques for suppressing the BPD expansion. We have discussed ion implantation techniques to reduce the carrier lifetime in drift layers, 43,44) and recently presented proton implantation as a novel approach. [45][46][47] This paper reviews the mechanisms behind dislocation mobility reduction and effects of ion/ proton implantation on suppressing the BPD expansion.…”

Development of an angle detection system for channeling implantation to the c-axis of SiC using birefringence phenomenon

“…2) The shallow ion implantation depth poses difficulties to fabricate super-junction structure, because number of repetition of ion implantation and epitaxial growth processes will be large. 3,4) To achieve deep ion implantation, high acceleration energies of ions or the utilization of ion channeling phenomenon is required. However, the development of high energy ion implanters is difficult, and high energy ion bombardments result in significant densities of defects in SiC.…”