Design and fabrication of 10-kV silicon–carbide p-channel IGBTs with hexagonal cells and step space modulated junction termination extension*

Abstract

10-kV 4H–SiC p-channel insulated gate bipolar transistors (IGBTs) are designed, fabricated, and characterized in this paper. The IGBTs have an active area of 2.25 mm2 with a die size of 3 mm × 3 mm. A step space modulated junction termination extension (SSM-JTE) structure is introduced and fabricated to improve the blocking performance of the IGBTs. The SiC p-channel IGBTs with SSM-JTE termination exhibit a leakage current of only 50 nA at −10 kV. To improve the on-state characteristics of SiC IGBTs, the hexagonal cell (H-cell) structure is designed and compared with the conventional interdigital cell (I-cell) structure. At an on-state current of 50 A/cm2, the voltage drops of I-cell IGBT and H-cell IGBT are 10.1 V and 8.3 V respectively. Meanwhile, on the assumption that the package power density is 300 W/cm2, the maximum permissible current densities of the I-cell IGBT and H-cell IGBT are determined to be 34.2 A/cm2 and 38.9 A/cm2 with forward voltage drops of 8.8 V and 7.8 V, respectively. The differential specific on-resistance of I-cell structure and H-cell structure IGBT are 72.36 m Ω · cm 2 and 56.92 m Ω · cm 2 , respectively. These results demonstrate that H-cell structure silicon carbide IGBT with SSM-JTE is a promising candidate for high power applications.

Morphological Transition of Vicinal 4H-SiC Surface Observed during Repeated Annealing

“…Silicon carbide (SiC), as a versatile functional material in the power and optoelectronic fields, 1,2 has been attracting sustained attention on its structural properties and preparation techniques. 3−6 High-quality SiC homoepitaxy is generally obtained by stacking sequence of SiC on off-axis (0001) (usually 4−8°off) faces through step flow growth.…”

“…Silicon carbide (SiC), as a versatile functional material in the power and optoelectronic fields, , has been attracting sustained attention on its structural properties and preparation techniques. − High-quality SiC homoepitaxy is generally obtained by stacking sequence of SiC on off-axis (0001) (usually 4–8° off) faces through step flow growth. , During this process, step bunching is apt to become serious when the off-axis angle gets lower. , According to the morphology characterization of epilayers, self-organization periodic nanofacets were frequently observed, and the width of nanofacets was suggested to be possibly controlled by selecting the SiC polytype, the vicinal angle, and the etching temperature. , In addition, localized faceting with relatively large steps could also occur and thus result in surface morphology with complex patterns . Despite the existence of surface examinations, the underlying mechanisms and controlling factors have not been understood thoroughly.…”

Role of remote Coulomb scattering on the hole mobility at cryogenic temperatures in SOI p-MOSFETs*

“…The transport property of carriers is essential to modeling [20,21] and simulation [22,23] of the MOSFETs. [24][25][26][27] There has been extensive research into the surface roughness scattering limited mobility, [28,29] while few attention has been paid to the impacts of remote Coulomb scattering on the hole mobility at cryogenic temperatures.…”