Gate Electrode Etching Stop Layer for Semiconductor Short-Circuit Prevention
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Solution Overview
Problem
In semiconductor device fabrication, the self-aligned contact process faces challenges with short-circuit issues due to insufficient selectivity between layer qualities during contact hole formation, particularly between the gate electrode and source/drain contacts, leading to reliability and process margin concerns.
Innovation Solution
The semiconductor device incorporates an etching stop layer with excellent etching resistance, such as aluminum oxide, to protect the upper part of the gate electrode during the contact hole formation process, ensuring effective prevention of short-circuits and improving the integration density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an etching stop layer with excellent etching resistance is added to protect the gate electrode during contact hole formation, then short-circuit prevention and reliability are improved, but device structure complexity increases
Solution Approach 1:
The gate electrode structure is segmented into multiple functional layers: the original gate electrode, an etching stop layer with excellent etching resistance (such as aluminum oxide) deposited on the gate electrode, and a capping pattern with lower etching resistance on the etching stop layer. This segmentation allows each layer to perform its specific function - the etching stop layer protects the gate electrode during contact hole formation while the capping pattern enables selective etching, thereby improving reliability without requiring complete structural redesign
Solution Approach 2:
The etching stop layer acts as an intermediary between the gate electrode and the etching process. This intermediate layer with excellent etching resistance protects the gate electrode from direct exposure to etchants during contact hole formation, preventing short-circuits. The capping pattern then serves as another intermediary that enables selective removal of specific regions, facilitating the etching process while maintaining gate electrode protection
2Manufacturing precision
If the gate electrode is fully protected during contact hole formation, then manufacturing precision and reliability improve, but process complexity and time increase
Solution Approach 1:
Instead of uniformly protecting the entire gate electrode structure, the capping pattern is applied locally on specific regions of the etching stop layer. This local quality approach allows selective etching in contact hole formation regions while maintaining protection in other areas, improving manufacturing precision for contact hole formation without requiring complete structural redesign or excessive process steps
Solution Approach 2:
The etching stop layer with excellent etching resistance is deposited on the gate electrode before the contact hole formation process begins. This preliminary protective action ensures the gate electrode is already protected when the etching process starts, preventing short-circuits from the outset. The subsequent capping pattern formation and selective etching then proceed with predetermined 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
This solution effectively prevents short-circuits between the gate electrode and source/drain contacts, enhancing the reliability and process margin of the semiconductor device by utilizing an etching stop layer that provides adequate protection and etching selectivity.
Implementation Method 1
an etching stop layer which wraps a side wall and an upper surface of an upper part of the gate electrode
Data Source
AI summary
A semiconductor device includes a fin type pattern extending in a first direction on a substrate, a field insulating layer on the substrate, the field insulating layer wrapping a side wall of the fin type pattern, a gate electrode on the fin type pattern, the gate electrode extending in a second direction intersecting with the first direction, a first spacer on a side wall of a lower part of the gate electrode, and an etching stop layer extending along a side wall and an upper surface of an upper part of the gate electrode, along a side wall of the first spacer, and along an upper surface of the field insulating layer.