Bipolar non-punch-through power semiconductor device

Abstract

Bipolar non-punch-through power semiconductor devices are provided. It comprises a semiconductor wafer (2) and a first electrical contact on a first main side and a second electrical contact on a second main side. The wafer (2) comprises an inner region (22) having a wafer thickness (23), and a termination region (24), which surrounds the inner region (22) and wherein the wafer thickness (23) passes at least on the first main side through the negative beveled and reduced. The semiconductor wafer (2) comprises at least a two-layer structure with layers of different conductivity types: - a drift layer (26) of a first conductivity type, a first layer of a second conductivity type, on the first main side connected directly to the drift layer (26) and contacts a first electrical contact, the first layer extending to the depth of the first layer, and a second layer of the second conductivity type arranged on the first main side to terminate the region (24) until the second layer depth. The second layer depth is greater than the first layer depth, which is at most 45 µm. The doping concentration of the second layer is lower than that of the first layer.

Description

Technical field [0001] The present invention relates to the field of power electronic devices and more specifically to bipolar non-punch-through power semiconductor devices and methods for manufacturing such power semiconductor devices. Background technique [0002] In US 5,710,442 a phase-controlled thyristor (PCT) 10 with a wafer 2 is described, on which a cathode contact 3 is arranged on the cathode side 31. The anode contact 4 is formed on the anode side 41 of the wafer opposite the cathode side 31. Inside the wafer 2, an (n-) doped drift layer 26 is arranged. A p-doped base layer 5 is provided on this drift layer 26 towards the cathode side 31 and contacts the cathode contact 3. The (N+) doped cathode layer 7 and the (p+) short region 8 are embedded in the base layer 5. They also contact the cathode electrode 3. Transverse to the cathode contact 3 and separated from it by the drift layer 26 is the arranged gate contact 95. [0003] On the anode side 41, a p-doped anode la...

AI Technical Summary

Problems solved by technology

[0007] Since the angle (where the thickness of the edge layers 50, 60 decreases) is small (approximately 2º) in order to slowly reduce the electric field towards the lateral edges of the device, and since the base layer depth 51 is chosen to be lower than the first edge layer depth 59 deeper, high losses develop in the inner region 22 (active area) of the device

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