A method for forming nitride films among polycrystalline silicon in a groove-type double layer grid MOS
A polysilicon and nitride film technology, applied in electrical components, semiconductor/solid-state device manufacturing, circuits, etc., can solve problems such as difficulty in controlling the thickness of the dielectric layer
Active Publication Date: 2014-03-12
SHANGHAI HUAHONG GRACE SEMICON MFG CORP
View PDF5 Cites 5 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
By using the nitride film as the isolation medium, it can solve the problem that the thickness of the dielectric layer between the two polysilicon layers is difficult to control, and improve the stability of the performance of the trench type double-layer gate power MOS device
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0052] The method for forming the nitride film dielectric layer between the two layers of polysilicon in the trench type double-layer gate MOS in the present invention comprises steps:
[0053] 1) Groove etching on the silicon wafer;
[0054] 2) Using thermal oxygen or low-pressure chemical vapor deposition, the oxide film dielectric layer is grown on the inner wall of the trench and the surface of the silicon wafer, with a thickness of 500-3000 angstroms;
[0055] 3) On the dielectric layer in the trench, grow the first layer of polysilicon by low-pressure chemical vapor deposition, wherein the thickness of the first layer of polysilicon is sufficient to fill the inside of the trench;
[0056] 4) Perform the first step of reverse etching on the first layer of polysilicon until it is etched to the silicon surface;
[0057] 5) Perform photolithography on the first layer of polysilicon to protect the position where the source polysilicon needs to be connected, and perform a sec...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
| Property | Measurement | Unit |
|---|---|---|
| thickness | aaaaa | aaaaa |
| thickness | aaaaa | aaaaa |
Login to View More
Abstract
The invention discloses a method for forming nitride films among polycrystalline silicon in a groove-type double layer grid MOS. The method comprises the following steps: 1), groove etching is carried out; 2), a dielectric layer grows; 3), a first layer of polycrystalline silicon grows; 4) a first step of reverse etching is carried out on the first layer of the polycrystalline silicon; 5), photoetching and a second step of reverse etching are carried out on the first layer of the polycrystalline silicon; 6), a nitride film is deposited; 7), after an HDP oxide-film is deposited, chemically mechanical polishing is carried out; 8), P-cover photoetching is carried out; 9), HDP oxide-film reverse etching is carried out; 10), the nitride film above a protective layer of the nitride film is removed; 11), a protective layer of the nitride film and the dielectric layer above the nitride film are removed; 12) a grid oxide layer grows; 13) a second layer of polycrystalline silicon is deposited and reverse etching is carried out; 14), a base electrode and a source electrode form; 15) contact apertures, metal and a passivation layer form. According to the invention, a problem that the dielectric layer between two layers of polycrystalline silicon is hard to control is solved, and the stability of a double-layer grid power MOS device is raised.
Description
technical field [0001] The invention relates to a method for forming a nitride film dielectric layer in the semiconductor field, in particular to a method for forming a nitride film dielectric layer between two layers of polysilicon in a trench type double-layer gate MOS. Background technique [0002] Among power devices, trench double-layer gate power MOS devices have the characteristics of high breakdown voltage, low on-resistance, high conversion efficiency and fast switching speed. Usually, the polysilicon electrode of the first layer is used as a shielding electrode and is short-circuited with the source or drawn out separately, and the polysilicon electrode of the second layer is used as a gate. The thickness of the oxide layer between the two polysilicon electrodes needs to be strictly controlled, otherwise leakage or lower breakdown voltage will occur. [0003] At present, the preparation method of the oxide layer between two layers of polysilicon electrodes in the ...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Applications(China)
IPC IPC(8): H01L21/285
CPCH01L29/42364
Inventor 李陆萍张博
Owner SHANGHAI HUAHONG GRACE SEMICON MFG CORP