Memory Stack Blind-Hole Etching for Uniform Capacitor Hole Contours
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Solution Overview
Problem
The existing manufacturing methods for semiconductor devices result in capacitor holes with poor contours due to uneven etching, leading to reduced memory yield and increased risk of short circuits or collapse.
Innovation Solution
A manufacturing method that involves forming a film stack structure on a substrate, creating a mask structure with a pattern transfer layer and a mask layer, performing a first etching to form first blind holes, and then a second etching to flatten the top surface of the pattern transfer layer and trim the bottoms of the first blind holes, ensuring vertical and uniform contours of the capacitor holes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single etching process is used to form capacitor holes, then the manufacturing process is simple, but the contour of the capacitor holes is poor and non-uniform
Solution Approach 1:
The etching process is divided into two distinct stages: a first etching process that forms blind holes through the mask structure, and a second etching process that removes the mask layer and trims the blind holes to form the final capacitor holes. This segmentation allows each etching step to be optimized independently, with the first step creating the initial cavity and the second step refining the contour and depth, thereby achieving uniform vertical walls while managing process complexity through structured multi-step fabrication
Solution Approach 2:
The first etching process performs a preliminary action by forming blind holes that extend through the mask structure and terminate in the cover layer, creating a pre-shaped cavity before the final etching step. This preliminary structuring allows the second etching process to focus on refining the contour and achieving the precise final shape, rather than having to create the entire structure in one step, thus improving contour uniformity while maintaining reasonable process complexity
2Manufacturing precision
If the mask layer is not removed after first etching, then the process is simpler, but the top surface of the pattern transfer layer remains uneven affecting subsequent processing
Solution Approach 1:
The second etching process performs a preliminary flattening action by removing the mask layer and trimming the blind holes, creating a flat top surface on the pattern transfer layer before subsequent processing steps. This preliminary surface preparation ensures that following lithography and etching steps can proceed with uniform starting conditions, improving manufacturing precision while the integrated nature of the process minimizes additional cycle time
Solution Approach 2:
The second etching process combines multiple functions into a single step: it removes the mask layer completely, trims the blind holes to the final depth, and flattens the top surface of the pattern transfer layer simultaneously. This merging of functions achieves the flat surface requirement without adding separate processing steps, thereby maintaining productivity while improving manufacturing precision
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
The method achieves capacitor holes with regular contours, improving the yield and reducing the likelihood of short circuits or collapse, resulting in better product performance.
Implementation Method 1
performing a first etching on the mask structure to form first blind holes; and performing a second etching on the mask structure, and removing the mask layer
Data Source
AI summary
The present disclosure provides a manufacturing method of a semiconductor device, including: providing a substrate; forming a film stack structure on the substrate, a top of the film stack structure being a cover layer; forming a mask structure on the cover layer, the mask structure including a mask layer and a pattern transfer layer sequentially stacked from top to bottom; performing a first etching on the mask structure to form first blind holes, the first blind holes running through the mask structure and terminating in the cover layer; and performing a second etching on the mask structure, and removing the mask layer, to flatten a top surface of the pattern transfer layer and trim bottoms of the first blind holes.