Collector Engineered Bidirectional Insulated Gate Bipolar Transistor With Low Loss

• Published in: IEEE transactions on electron devices Vol. 69; no. 3; pp. 1604 - 1607
• Main Authors: Vaidya, Mahesh, Naugarhiya, Alok, Verma, Shrish, Mishra, Guru Prasad
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-03-2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Bidirectional; Breakdown; Buffer layers; Doping; Drift; Electric breakdown; Electric fields; Fabrication; insulated gate bipolar transistor (IGBT); Insulated gate bipolar transistors; Leakage current; Leakage currents; Logic gates; ON-state voltage; p-buffer; semi-superjunction (Semi-SJ); Semiconductor devices; Transistors
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2022.3141989

The collector engineered bidirectional insulated gate bipolar transistor (CEB-IGBT) with p-buffer and semi-superjunction (Semi-SJ) is proposed. The structural modification at collector side provides support to reverse breakdown voltage (<inline-formula> <tex-math notation="LaTeX">\text {BV}_{R} </tex-math></inline-formula>) in two ways. First, the p-buffer layer allows the device to deplete completely and eliminates premature breakdown effects. Second, the Semi-SJ region introduces an electric field component in the <inline-formula> <tex-math notation="LaTeX">{x} </tex-math></inline-formula>-direction (<inline-formula> <tex-math notation="LaTeX">{E}_{X} </tex-math></inline-formula>) in order to further improve the <inline-formula> <tex-math notation="LaTeX">\text {BV}_{R} </tex-math></inline-formula>. The overall increased electric field, which is a resultant of <inline-formula> <tex-math notation="LaTeX">{E}_{X} </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">{E}_{Y} </tex-math></inline-formula>, improves <inline-formula> <tex-math notation="LaTeX">\text {BV}_{R} </tex-math></inline-formula> by 53.83% compared to nonpunchthrough IGBT (NPT-IGBT). The efficient potential distribution in the drift region provides support to forward breakdown (<inline-formula> <tex-math notation="LaTeX">\text {BV}_{F} </tex-math></inline-formula>) as well. The n-layer below p-body acts as a field stop (FS) layer, which reduces the leakage current during the OFF-state condition. The p-buffer, which injects higher minority charges along the drift side and n-layer with charge storage effect collectively, provides conductivity modulation in the epitaxial region in order to increase current handling capability. This high collector current density leads to reduce <inline-formula> <tex-math notation="LaTeX">{V}_{ \mathrm{\scriptscriptstyle ON}} </tex-math></inline-formula> by 14.5% compared to NPT-IGBT. Furthermore, the charge coupling effect of Semi-SJ region enables the proposed device to turn-off quickly with higher pillar doping and reduces turn-off loss (<inline-formula> <tex-math notation="LaTeX">{E}_{ \mathrm{\scriptscriptstyle OFF}} </tex-math></inline-formula>) in comparison with NPT-IGBT.