Semiconductor Pad Structure to Prevent Under-Etching
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Solution Overview
Problem
The scaling down of semiconductor devices poses challenges in achieving improved quality, yield, performance, and reliability while reducing complexity, particularly due to issues such as under etching during blanket metal etch processes.
Innovation Solution
A semiconductor device with a pad structure featuring a bottom portion and side portions extending parallel to the substrate surface, surrounded by an insulator film, and a method for fabricating this structure involving the formation of pre-defined pad openings and subsequent conductive material deposition and etching to prevent under etching risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional blanket metal etch processes are used, then manufacturing simplicity is maintained, but under etching occurs leading to reduced manufacturing precision
Solution Approach 1:
The pad structure is formed with pre-defined pad openings in the insulator film before the blanket metal etch process. This preliminary structuring of the pad region provides etch stop features that prevent under-etching during subsequent metal deposition, thereby improving etch precision without requiring complex real-time control during etching
Solution Approach 2:
The pad structure is segmented into distinct components: a bottom portion embedded in the insulator film and side portions extending upward. This segmentation creates defined geometric features that serve as etch stops, allowing the etch process to be precisely controlled at different depths in different regions, thus improving overall etch precision
2Productivity
If device dimensions are scaled down, then computing ability is improved, but fabrication yield and reliability deteriorate
Solution Approach 1:
The pad structure with pre-formed pad openings is created before scaling-related miniaturization challenges affect the fabrication process. This preliminary structuring establishes reliable etch stop references that remain effective even as overall device dimensions are reduced, maintaining fabrication yield during scaling
Solution Approach 2:
The insulator film surrounding the pad structure acts as an intermediary element that provides mechanical and electrical isolation. This intermediary structure protects the scaled-down device components from fabrication defects, thereby maintaining reliability as dimensions are reduced
Data Source
AI summary
The present application discloses a semiconductor device and a method for fabricating the semiconductor device. The semiconductor device includes a substrate; a pad structure positioned above the substrate and including a bottom portion and two side portions, wherein the bottom portion is positioned parallel to a top surface of the substrate, and the two side portions are positioned on two sides of the bottom portion and extending along a direction parallel to a normal of the top surface of the substrate; and an insulator film surrounding the pad structure. A top surface of the insulator film is at a vertical level greater than a vertical level of a top surface of the pad structure.