Method For Fabricating Good Quality Continuous Thin Polycrystalline Silicon Films
Original Publication Date: 1979-Sep-01
Included in the Prior Art Database: 2005-Feb-20
Polycrystalline silicon (poly-Si) thin films have been used extensively for contacts in shallow structures and fast speed devices. However, in order to obtain a continuous and uniform poly-Si film, the film invariably exceeds the required thickness that is needed to satisfy the solid solubility of the metal over the contacts. Thus, after the formation of the metal silicide, the remaining layer of poly-Si film gives an overall increase in the vertical dimension of the device, for example, the polySi layer left over the emitter contact region in a bipolar transistor. This increase in thickness of the emitter causes a reduction in speed and efficiency of the transistor. It is, therefore, desirable to have a method which produces poly-Si films of 20 nanometers or less.