Method of manufacturing an integrated ULSI heatsink

Abstract

A simple and low cost ULSI integrated heatsink more efficiently removes heat from a silicon package by integrating the heat sink material into the silicon die, transforming the present two-dimensional art into three dimensions. The fabrication of a high power integrated ULSI package and heatsink begins by fabricating an integrated circuit wafer up to the point of dicing the wafer into individual chips. The front side of the wafer is protected, while the backside of the wafer is exposed. The exposed backside is roughened by chemical and/or mechanical process. Optionally, a gettering process is then performed to remove impurities. The roughened backside is then coated with metal interlayers, preferably aluminum (Al) by chromium (Cr). A layer of copper (Cu) is optionally coated on the metal interlayers. A highly conductive reflowable material, such as solder or gold eutectic, is deposited on the metal interlayers. At this point, the wafer is diced to form chips. The heatsink itself is prepared by first optionally roughening the surface and metalizing the backside of the heatsink with metal interlayer. Next, the chip is thermally attached to the heatsink by reflowing the thermally conductive reflowable material.

Dependencies are inferred from the claim text.