Single Mask Trench Formation for Vertical Transfer Gates
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Solution Overview
Problem
The existing methods for forming a vertical transfer gate and isolation structure on a semiconductor substrate require at least two critical masks, making the manufacturing process costly and time-consuming.
Innovation Solution
A method is developed to form at least two trenches with different depths in a semiconductor substrate using a single critical mask, where the first and second openings have equal or different widths, allowing for the formation of a vertical transfer gate and isolation structure with reduced processing costs and time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If at least two critical masks are used to form the vertical transfer gate and isolation structure, then the manufacturing precision of both structures is ensured, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines the formation of the vertical transfer gate and isolation structure into a single etching process using one critical mask. The mask is designed with first and second openings that define both the transfer gate trench and isolation trench simultaneously, merging two previously separate critical steps into one unified process that maintains precision for both structures.
Solution Approach 2:
The single critical mask serves multiple functions by containing both the first opening for the vertical transfer gate and the second opening for the isolation structure. This universal mask design eliminates the need for separate masks, reducing device complexity while maintaining the ability to precisely define both trench types through its dual-opening configuration.
2Manufacturing precision
If at least two critical masks are used to form the vertical transfer gate and isolation structure, then the manufacturing precision of both structures is ensured, but the production time increases
Solution Approach 1:
The patent merges the formation of the vertical transfer gate and isolation structure into a single etching process using one critical mask. The mask is designed with first and second openings that define both the transfer gate trench and isolation trench simultaneously, merging two previously separate critical steps into one unified process that maintains precision for both structures.
Solution Approach 2:
The single critical mask is designed in advance with both the first opening and second opening configured to create the precise dimensions and positions of both the vertical transfer gate and isolation structure. This preliminary design of the mask with dual functionality allows both structures to be formed correctly in one etching step, eliminating the time required for sequential mask applications.
3Manufacturing precision
If at least two critical masks are used to form the vertical transfer gate and isolation structure, then the manufacturing precision of both structures is ensured, but the manufacturing cost increases
Solution Approach 1:
The patent combines the formation of the vertical transfer gate and isolation structure into a single etching process using one critical mask. The mask is designed with first and second openings that define both the transfer gate trench and isolation trench simultaneously, merging two previously separate critical steps into one unified process that maintains precision for both structures.
Solution Approach 2:
The single critical mask serves multiple functions by containing both the first opening for the vertical transfer gate and the second opening for the isolation structure. This universal mask design eliminates the need for separate masks, reducing device complexity while maintaining the ability to precisely define both trench types through its dual-opening configuration.
Data Source
AI summary
Methods of forming trench structures of different depths in a semiconductor substrate are provided. A first mask forming a first opening and a second opening is provided on the semiconductor substrate. The semiconductor substrate is etched through the first and second openings, thereby forming a first trench and a second trench. Trench structure material is deposited in the first and second trenches, thereby forming first and second trench structures. A second mask is provided on the first mask, wherein the second mask covers the first opening and has a third opening superimposed over the second opening of the first mask. The second trench structure is etched through the second opening of the first mask and through the third opening of the second mask.