摘要:
In the method of the invention a patterned first carbon cap layer (2') is used as an implantation mask for implantion of impurities into a silicon carbide layer (1). After activation of the implanted impurities by annealing the same patterned first carbon cap layer (2') is also used a deposition mask for depositing a metal layer (20) onto the silicon carbide layer (1). Due to the use of one and the same mask as an implantation mask and as a deposition mask, a self-aligned ohmic contact (30) to a doped well region (9) can be formed. Therein, the same first opening (7) in the patterned first carbon cap layer (2') is used to define a position of the doped well region (9) and a position of the self-aligned ohmic contact (30).
摘要:
A high power, high current Unidirectional Transient Voltage Suppressor, formed on SiC starting material is disclosed. The device is structured to avalanche uniformly across the entire central part (active area) such that very high currents can flow while the device is reversely biased. Forcing the device to avalanche uniformly across designated areas is achieved in different ways but consistently in concept, by creating high electric fields where the device is supposed to avalanche (namely the active area) and by relaxing the electric field across the edge of the structure (namely in the termination), which in all embodiments meets the conditions for an increased reliability under harsh environments.
摘要:
The subject matter disclosed herein relates to silicon carbide (SiC) power devices and, more specifically, to SiC super-junction (SJ) power devices. A SiC-SJ device includes a plurality of SiC semiconductor layers of a first conductivity-type, wherein a first and a second SiC semiconductor layer of the plurality of SiC semiconductor layers comprise a termination region disposed adjacent to an active region with an interface formed therebetween, wherein the termination region of the first and the second SiC semiconductor layers comprises a plurality of implanted regions of a second conductivity-type, and wherein an effective doping profile of the termination region of the first SiC semiconductor layer is different from an effective doping profile of the termination region of the second SiC semiconductor layer.
摘要:
Methods and systems for lateral power devices, and methods for operating them, in which charge balancing is implemented in a new way. In a first inventive teaching, the lateral conduction path is laterally flanked by regions of opposite conductivity type which are self-aligned to isolation trenches which define the surface geometry of the channel. In a second inventive teaching, which can be used separately or in synergistic combination with the first teaching, the drain regions are self-isolated. In a third inventive teaching, which can be used in synergistic combination with the first and/or second teachings, the source regions are also isolated from each other. In a fourth inventive teaching, the lateral conduction path is also overlain by an additional region of opposite conductivity type.
摘要:
A method of manufacturing a semiconductor with very deep doping structures, comprising the steps of: a) providing a substrate having an upper surface comprising at least one trench, b) adding material to the substrate using epitaxial growth, c) removing material from the top of the substrate to a level below the original upper surface in step a), d) adding material to the substrate using epitaxial growth, e) removing material from the top of the substrate to a level at or below the level after step c). One feature is that the method can be performed with fewer epitaxy steps and is thus less expensive and faster.
摘要:
A method for manufacturing a power semiconductor device is provided. The method comprises the following steps: providing a wafer (41) of a first conductivity type, the wafer (41) having a first main side (42) and a second main side (43) opposite to the first main side (42), and the wafer (41) including an active cell area (44), which extends from the first main side (42) to the second main side (43), in a central part of the wafer (41) and a termination area (45) surrounding the active cell area (44) in an orthogonal projection onto a plane parallel to the first main side (42); forming a metallization layer (46; 86) on the first main side (42) to electrically contact the wafer (41) in the active cell area (44), wherein the surface of the metallization layer (46; 86), which faces away from the wafer (41), defines a first plane (B) parallel to the first main side (42); forming an isolation layer (417) on the first main side (42) in the termination area (45), wherein the surface of the isolation layer (417) facing away from the wafer (41) defines a second plane (A) parallel to the first main side (42); after the step of forming the metallization layer (46; 86) and after the step of forming the isolation layer (417), mounting the wafer (41) with its first main side to a flat surface of a chuck (421); and thereafter thinning the wafer (41) from its second main side (43) by grinding while pressing the second main side of the wafer (41) onto a grinding wheel (422) by applying a pressure between the chuck (421) and the grinding wheel (422), wherein the first plane (B) is further away from the wafer (41) than a third plane, which is parallel to the second plane (A) and arranged at a distance of 1 μιη from the second plane (A) in a direction towards the wafer (41).