SOI type MOS element and manufacturing method thereof
AssigneeOki Electric Industry Co., Ltd.
InventorNorio Murakami
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Abstract
To present a SOI type MOS element excellent in yield, performance and characteristic, easy in manufacture, and low in cost, and a method of manufacturing the same. A SOI type MOS transistor structure comprising polysilicon electrodes 128 for gate, source and drain composed by burying into trench holes 120a, 120b, 120c respectively formed in a semiconductor substrate 110, a gate oxide film 122 formed in the entire inside of the trench hole 120a, N− diffusion layer 124 and N+ diffusion layer 126 formed in the entire inside of the trench holes 120b and 120c, and a thick SiO2 film 114 in a trench hole 113 formed in the semiconductor substrate 110 so as to surround the transistor.
Claims6
A manufacturing method for an MOS element comprising:
- a step of preparing a P type or N type semiconductor substrate,
- a step of forming a fourth trench around a region for forming an MOS transistor in the semiconductor substrate,
- a step of burying a SiO2 layer in the fourth trench,
- a step of forming first, second and third trenches in a region surrounded by the SiO2 layer,
- a step of forming a gate oxide film on the entire surface of the inside of the first trench,
- a step of forming an N type impurity layer on the entire surface of the inside of the second and third trenches, and
- a step of burying a conductive polysilicon film in the first, second and third trenches to form gate, source and drain electrodes, respectively.
Dependencies are inferred from the claim text.