Method of Forming Aluminum Films Having Regions With a Defined Surface Topography
Original Publication Date: 1985-Jan-01
Included in the Prior Art Database: 2005-Feb-18
On an aluminum film, deposited on a silicon wafer, hillocks are grown at least in selected regions defined by silicon surface areas that have been selectively boron-doped prior to the deposition of aluminum. The silicon wafer is boron-doped in surface areas where the hillocks are to be formed in a later step. Onto the silicon wafer, an aluminum film is deposited, followed by a temperature step at values ranging from about 350 to about 400ŒC, at which the hillocks grow. The hillock density is influenced by the boron doping level of the substrate. In the range of 1018 to 1020 boron atoms/cm3, the hillock density varies by a factor 6.