| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method for an IGBT that can suppress positive feedback between the temperature rise of the IGBT and operating current increase. SOLUTION: A cross current Ic=Nq(μeRT+μhRT)s(VfRT-VfHT)/d, where N is conductivity modulation density, (q) an electron charge,μeRT electron mobility at room temperature,μhRT positive hole mobility at room temperature, (s) the cross-sectional area of an n+ buffer layer and an n- layer 4 (Fig. 2), (d) the thickness of the n+ buffer layer and n- layer 4, VfRT the operating voltage at room temperature, and VfHT the operating voltage at high temperature. The conductivity modulation density N is so determined that the cross current Ic is smaller than the operating current Iop/m (m: the number of IGBTs connected in parallel), and n+ buffer layer density nb and n+ buffer layer thickness db are so determined as to obtain the conductivity modulation density N. COPYRIGHT: (C)2006,JPO&NCIPI
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