Method of joining a wafer-type semiconductor body over a large area to a metallic substrate disc

摘要

To join the semiconductor body (3) of a power semiconductor component over a large area to a metallic substrate disc (4), both the back boundary surface (9) of the semiconductor body (3) and the front (10) of the substrate disc (4) are polished to such an extent that they exhibit only a few Newton rings in the interference pattern. An adhesive base layer (19, 20) composed, for example, of titanium and having a thickness of approximately 40 A is then vapour-deposited on each of the polished surfaces (9, 10) in a vacuum system (5-8 and 12-17). Gold layers (23, 24) approximately 60 Ä thick are then vapour-deposited in each case on these layers (19, 20) and said gold layers (23, 24) are placed one on top of the other at room temperature.