| 摘要 |
PURPOSE:To enable reduction of a bird's beak in size and to facilitate minituarization of the MOS semiconductor device by forming a substance consisting of Si oxide mainly only in a region except element forming regions. CONSTITUTION:A masking substance 22 is formed on a first conductive type Si substrate 21 followed by photo-etching to selectively leave the masking substance 22 only in element forming regions 22a-22c. After the element isolation regions 23a and 23b are etched to the predetermined depth to remove the masking substances 22a-22c, solution consisting of Si compound mainly is spread followed by heat treatment. Consequently, the solution consisting of Si compound mainly changes into substances 24c and 24d consisting of Si oxide mainly to become a stable solid substances. After that, a gate electrode 27 and source and drain regions 28a and 28b are formed. Thus, accuracy in formation of the element isolation region is almost determined by accuracy in etching of the Si substrate 21. If etching of high anisotropy is used, formation in the region to be determined based on the masking substance becomes possible. |
