Semiconductor Mask Opening Adjustment for Precise Recess Alignment
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Solution Overview
Problem
Existing methods struggle to accurately adjust the position and dimension of recess portions in semiconductor devices during manufacturing, leading to potential misalignment and inefficiencies.
Innovation Solution
A method involving the formation of openings in a mask film, selective etching of side surfaces, and application of a second mask film to adjust the dimensions and position of these openings, followed by forming recess portions using the mask films as a mask.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional methods are used to form recess portions, then the manufacturing process is simple, but the position and dimension of recess portions cannot be accurately adjusted
Solution Approach 1:
The mask film is divided into multiple segments (first mask film and second mask film) that can be independently processed. The first mask film defines initial openings, while the second mask film modifies these openings to achieve precise dimensional control. This segmentation allows separate optimization of each mask layer's function, enabling accurate recess portion formation without requiring complete process redesign.
Solution Approach 2:
The first mask film is formed and processed in advance to define the initial opening positions and rough dimensions. This preliminary masking structure serves as a foundation for subsequent processing steps. By preparing the first mask film beforehand with predetermined opening locations, the method enables controlled modification in later steps to achieve final precise dimensions, rather than attempting to create the final structure in a single step.
2Manufacturing precision
If the opening dimension is adjusted by direct etching, then the process is simple, but the alignment with film stack becomes inaccurate
Solution Approach 1:
The first mask film acts as an intermediary structure between the opening definition step and the final recess formation. It provides a controllable intermediate state where openings can be formed with predetermined dimensions and positions. This intermediary mask layer enables controlled material removal in subsequent steps while maintaining alignment accuracy, serving as a buffer that decouples the simplicity of direct etching from the precision requirements of final structure formation.
Solution Approach 2:
The mask film structure is designed with different properties in different regions: the first mask film provides broad area coverage with predetermined opening patterns, while the second mask film provides localized dimensional adjustment at specific opening locations. This local differentiation allows precise control of opening dimensions where needed while maintaining overall process efficiency, rather than applying uniform processing across the entire structure.
3Manufacturing precision
If multiple mask films are used to adjust opening dimensions, then the precision of recess portions is improved, but the manufacturing complexity increases
Solution Approach 1:
The formation of openings and the adjustment of opening dimensions are merged into an integrated two-stage masking process. The first mask film defines opening positions, and the second mask film adjusts dimensions, with both functions accomplished through coordinated processing steps rather than separate operations. This merging allows the dual function of position definition and dimensional control to be achieved in a unified manufacturing flow, improving efficiency compared to completely separate processes.
Solution Approach 2:
The method transitions from two-dimensional planar masking to three-dimensional structured masking by forming openings with controlled depth and shape. The first mask film establishes the planar opening pattern, while the second mask film adds vertical dimensionality control through selective etching of mask film side surfaces. This dimensional transition enables precise control of recess portion geometry (width, depth, shape) that cannot be achieved with conventional planar masking alone, while maintaining manufacturing feasibility through systematic process design.
Data Source
AI summary
A method for manufacturing a semiconductor device includes providing a substrate including a first film stack, a dielectric film, and a first mask film, the first film stack being disposed in a first region on the substrate, the dielectric film being disposed on the substrate to cover the first film stack, and the first mask film being disposed on the dielectric film, forming a plurality of openings in the first mask film, at least one of the plurality of openings being formed at a position overlapping a part of the first film stack in a plan view of the substrate, and the first mask film including a plurality of side surfaces defining the plurality of openings, and etching the plurality of side surfaces of the first mask film.