公开(公告)号：JPH10289980A

公开(公告)日：1998-10-27

申请号：JP9920098

申请日：1998-04-10

Applicant: IBM

Inventor： LOUIS RUU CHEN FUU ,  MANDELMAN JACK ALLAN ,  FARIBORTZ ATSUSADERAHI

IPC: G11C11/00 ,  H01L21/8242 ,  H01L21/8244 ,  H01L21/8247 ,  H01L27/10 ,  H01L27/105 ,  H01L27/108 ,  H01L27/11 ,  H01L27/115 ,  H01L29/788 ,  H01L29/792

Abstract: PROBLEM TO BE SOLVED: To design a smart-card integrated circuit whose density is high, whose chip size is small and which is low-cost by a method wherein a semiconductor memory device which contains an NVRAM cell structure, a DRAM cell structure and an SRAM cell structure is formed on an identical substrate. SOLUTION: An NVRAM cell structure, a DRAM cell structure and an SRAM cell structure are formed on an identical substrate. In the NVRAM cell structure, a double polysilicon layer is used as the topology of a stacked capacitor DRAM and as a material layer, a staked capacitor is formed, and shallow trench isolation regions 26, 28 are formed on the substrate adjacent to a source region and a drain region inside the substrate. In the DRAM cell structure, a source region, a drain region and a trench isolation region 28 are contained, and a gate structure which is the same as in the VRAM cell structure and a stud interconnection are contained. In the SRAM cell structure, a source region and a drain region which are the same as in the NVRAM cell structure and the DRAM cell structure are contained, and a stud interconnection is contained.