Abstract: Vertically oriented thermal processor, also known as a vertical diffusion furnace for the processing of silicon or gallium arsenide wafers or substrates including a vertically positionable furnace assembly, and a quartz bell-jar shaped element which positions coaxially over and about another quartz bell jar like vertically positionable process tube forming a dual wall contamination barrier. The furnace and the process tube bell jar can be moved up and down pneumatically as a unit or independently of one another during processing modes. Pneumatic cylinders provide for the lifting of the furnace element away from the wafers to ramp temperatures downwardly at an accelerated rate. An overhead track positions for accelerated removal of the furnace and process tube to the exterior of the cabinet without disconnection of electrical, pneumatic or gas connections for maintenance or component changeout.

Abstract: In the fabrication of semiconductor devices, a method is provided which includes the steps of selectively doping a semiconductor substrate of one conductivity type to form therein discrete regions of opposite conductivity type, followed by selective epitaxial growth to fill the windows of the diffusion mask, whereby the epitaxially grown regions are inherently characterized by exact alignment with the doped regions. The self-aligned epitaxial structure is then subjected to further processing in accordance with numerous alternate schemes to provide a wide variety of devices.