Preparation method for flat cell rom device
AssigneeCsmc Technologies Fab2 Co., Ltd.
InventorsGuipeng SUN, Qiong WANG, Guangtao HAN
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Abstract
A preparation method for a flat cell ROM device, comprising the steps of: providing a substrate, and forming a P well on the substrate; forming a photomask layer on the P well and performing photoetching to form an injection window; injecting P-type ions in the formed injection window to form a P-type region; injecting N-type ions in the injection window so as to form an N-type region on the P-type region; and forming a gate oxide layer and a poly-silicon gate so as to complete the preparation of a device.
Claims10
A method of manufacturing a flat cell read-only memory (ROM) device, comprising the following steps of:
- providing a substrate;
- forming a P well on the substrate;
- forming a photolithography mask layer on the P well and performing photolithography to form an implantation window;
- performing P-type ion implantation to the implantation window by using the photolithography mask layer to form a P-type region;
- performing N-type ion implantation to the implantation window by using the photolithography mask layer to form an N-type region on the P-type region;
- wherein the N-type region comprises a first N-type region and a second N-type region;
- the first N-type region and the second N-type region serve as a source and a drain of the flat cell ROM device, respectively;
- forming a gate oxide layer on surfaces of the substrate and the N-type region;
- and
- forming a polysilicon gate on a surface of the gate oxide layer.
Dependencies are inferred from the claim text.