Patent ID: 6228745
Filing Date: 2001-05-08
Classification: H01L,Y10S

Abstract:
Method of making a semiconductor device, comprising:depositing a photoresist on a semiconductor substrate having a major dimension in a horizontal plane;patterning said photoresist with a phase-shifting mask having a line and at least two phase-shifting portions, one on each side of said line, said phase-shifting portions being so located relative to said line to produce a developed photoresist line pattern having sidewalls sloped at an angle between 75 and 30 degrees away from said major dimension as determined by controllable parameters of said phase-shifting portions;transferring said developed photoresist line pattern to said semiconductor substrate to define an active area for a semiconductor device having straight sidewalls sloped at an angle between 105 and 150 degrees away from said major dimension;filling trenches remaining from defining said active area with an isolation material;forming source, drain, and channel regions in said active area between said trenches; andforming a gate stack over said channel region, said gate stack being oriented transversely to sidewalls of said trenches.