Planar integration of laser‐recrystallized SOI‐Tr's fabricated by lateral seeding process and bulk‐Tr's and its application to fabrication of a solid‐state image sensor

Abstract

To realize functions which cannot be achieved by conventional integrated circuits composed of bulk transistors (bulk‐Tr), part of an integrated circuit was formed by laser‐recrystallized SOI transistors (SOI‐Tr) using the lateral seeding process. The uniqueness of this structure is that the bulk‐Tr's and SOI‐Tr's are formed in the same plane. To realize this planar structure, the necessary basic technology was developed and bulk‐Tr's and SOI‐Tr's were formed in the same plane to test the structure. The characteristics of the transistors were compatible to those of transistors formed by conventional MOS processes. For the application of this structure to integrated circuits, a solid‐state image sensor was fabricated where the driver circuits were formed by the bulk‐Tr's and the read‐out of the picture elements was carried out by using the SOI‐Tr's. As a result, a high‐quality image was obtained and the smear noise caused by photoleakage current was suppressed.