Semiconductor Cutout with Inclined Auxiliary Layer for Self-Aligned Structures
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Solution Overview
Problem
The semiconductor industry faces challenges in achieving smaller feature sizes while maintaining tight tolerance limits, particularly in self-aligned structure elements like contact holes for gate trench transistors, where existing methods like spacers and oxide masks result in large tolerances and require deeper trench production.
Innovation Solution
A method involving the creation of a semiconductor body with a cutout and auxiliary layers, where the first auxiliary layer is formed with a specific angle and material, and a second auxiliary layer is deposited to protect and define the structure, allowing for precise control of the layer's width and overlap, enabling small tolerance settings and precise spacings through selective removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If self-aligned production methods are used to reduce structure element sizes, then smaller feature sizes are achieved, but tolerance limits become difficult to meet
Solution Approach 1:
The method performs preliminary actions by forming the first auxiliary layer with inclined sidewalls that overhang the cutout before the actual structure element formation. This overhanging structure is created in advance to provide self-alignment and protect the cutout during subsequent processing steps, enabling precise positioning without requiring tight tolerances in later steps.
Solution Approach 2:
The auxiliary layers (first and second auxiliary layers) serve as intermediary structures that facilitate the formation of the final structure element. The first auxiliary layer with inclined sidewalls acts as a self-aligned mask and protective structure, while the second auxiliary layer provides additional protection and definition. These intermediary structures enable precise feature formation without directly requiring tight tolerances in the final structure.
2Manufacturing precision
If oxide masks are used for contact hole etching, then self-alignment is achieved, but gate trenches must be produced with greater depth
Solution Approach 1:
The invention transitions from relying on vertical oxide mask structures to using inclined sidewall structures that extend laterally over the cutout. The first auxiliary layer forms sidewalls with angles between 10°-80° that overhang the cutout, creating a self-aligned structure in the lateral dimension rather than relying on deep vertical trenches for mask formation.
Solution Approach 2:
The method forms the auxiliary layers with inclined sidewalls before performing the contact hole etching. This preliminary formation of self-aligned structures eliminates the need for deep gate trenches that would be required if using traditional oxide masks, as the self-alignment is achieved through the inclined geometry rather than through deep trench confinement.
3Ease of manufacture
If spacers are used for contact hole formation, then structure elements are formed, but tolerance limits are relatively large
Solution Approach 1:
The first auxiliary layer is formed with asymmetric inclined sidewalls that overhang the cutout, creating a non-symmetric structure with specific angle ranges (10°-80°). This asymmetric geometry provides self-alignment and precise positioning that eliminates the large tolerances associated with conventional symmetric spacer structures.
Solution Approach 2:
The invention changes the geometric parameters of the auxiliary layer structure by forming inclined sidewalls with specific angle ranges instead of vertical or tapered spacer structures. By controlling the sidewall angle and the overhang distance, the method achieves precise positioning and small tolerances that improve upon conventional spacer approaches.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method allows for the production of self-aligned structure elements with small tolerance limits, enabling precise control over spacings and feature sizes, suitable for use as a mask layer in further processing steps like etching or implantation, reducing the pitch between gate trenches and improving the design of semiconductor components.
Implementation Method 1
producing a first auxiliary layer on the surface and in the cutout in such a way that the first auxiliary layer forms a well above the cutout
Implementation Method 2
producing a second auxiliary layer within the well at the well base and at the at least one well sidewall
Data Source
AI summary
A semiconductor component includes a semiconductor body having a surface and a cutout in the semiconductor body. The cutout extends from the surface of the semiconductor body into the semiconductor body in a direction perpendicular to the surface. The cutout has a base and at least one sidewall. The component further includes a layer on the surface of the semiconductor body and in the cutout. The layer forms a well above the cutout. The well has a well base, a well edge and at least one well sidewall. The at least one well sidewall forms an angle α in the range of 20° to 80° with respect to the surface of the semiconductor body. The layer has at least one edge which, proceeding from the well edge, extends in the direction of the surface of the semiconductor body.