The pmc of polysilicon intended to structures of the dram cells has a high density

摘要

Producing memory device on substrate, which has a charge storage capacitor, includes the following: - Provide a transistor, which has already formed source/drain and gate electrode on its surface; - Deposit 1st insulating layer on transistor; - Deposit 2nd insulating layer, which has different material with 1st insulating, on 1st insulating layer; - Through 1st and 2nd insulating layer to provide 1st contact window to expose 1st source/drain of transistor; - Deposit 1st polysilicon on 2nd insulating layer, the 1st polysilicon is doing electrical contact with 1st source/drain of transistor; - Deposit 3rd insulating layer on 1st polysilicon layer, and image 3rd insulating layer to provide 2nd contact window to expose 1st polysilicon layer; - Deposit 2nd polysilicon to fill 2nd contact window; - Proceed polishing to remove redundant part of 2nd polysilicon; - Remove 3rd insulating layer to expose polysilicon superstructure vertically extended on 1st polysilicon layer, and form portion of bottom electrode of charge storage capacitor; - Form dielectric on top of polysilicon superstructure and 1st polysilicon layer; - Deposit 3rd polysilicon layer, and form upper electrode of charge storage capacitor.