Staas & Halsey
Method of manufacturing a semiconductor device
 A method of manufacturing a semiconductor device for simultaneously forming a plurality of diffused regions of selectively different diffusion depths, comprises forming polycrystalline semiconductor layers of corresponding, selectively different depths on the semiconductor substrate surface provided with a diffusion mask having a plurality of diffusion windows. By the impurity diffusion into the substrate through the windows at the polycrystalline semiconductor layer interface with the substrate, a comparatively shallow diffused region and a comparatively deep diffused region are formed simultaneously by a single diffusion process, respectively, under the comparatively thick polycrystalline semiconductor layer and the comparatively thin polycrystalline semiconductor layer. 
VLSI Technology Research Association
H H Y
H01L H01L Y10S
inventional inventional additional
Hirokazu Kazumasa
Suzuki Nawata