Fabrication Process for Advanced Bipolar Transistors
Original Publication Date: 1987-Feb-01
Included in the Prior Art Database: 2005-Feb-01
A method has been proposed to use a selective epitaxial growth process to form shallow oxide trench isolation in semiconductor devices. The procedure would replace the space consuming recessed oxide isolation (ROI) process. When ROI is used for shallow device isolation in advanced transistors, the existence of the bird's beak occupies valuable space and prevents junction butting to the isolation. In addition to loss of device density and the high temperature thermal cycle required with ROI, the bird's beak effect can adversely affect surface planarization. (Image Omitted) The new fabrication procedure utilizes a silicon selective epitaxial growth technique. In the process a thick SiO2 layer 1 is formed over the N+ 2 and P- 3 sublayers as seen in Fig. 1.