Gate structure of separation gate power device and process method
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI HUAHONG GRACE SEMICON MFG CORP
- Publication Date
- 2015-03-25
Smart Images
Figure 1 Figure 2 Figure 3
Abstract
Description
technical field
[0001] The invention relates to the field of design and manufacture of integrated circuits, in particular to a gate structure of a split gate power device, and also relates to a process method for the gate structure. Background technique
[0002] At present, power semiconductor devices using a split gate structure use polysilicon materials for the gate, such as figure 1 As shown, it is a schematic cross-sectional view of a split gate structure. The gate is a trench type. A gate oxide layer is deposited on the inner wall of the trench and then filled with polysilicon. The lower part has a split gate 5 and the upper part has a polysilicon gate 6 .
[0003] Polysilicon needs to be filled into holes (or trenches), and it is well known that polysilicon has a relatively poor hole-filling ability. holes will be formed, such as figure 2 (A cross-sectional micrograph of a trenched polysilicon gate) is circled. Even if there is no hole, a closed line will be formed...