Semiconductor Contact Etch Stop Structure Against Dielectric Punch-Through
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Solution Overview
Problem
Existing semiconductor fabrication processes face challenges in preventing punch through of dielectric layers during etch processes to form contacts, leading to issues such as short circuits and increased leakage.
Innovation Solution
The implementation of a blocking layer selectively formed on conductive features and an etch stop layer on adjacent dielectric layers to control etch processes, mitigating punch through and ensuring precise contact formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If etch process is performed to form contact through dielectric layer, then contact formation is achieved, but punch through occurs causing short circuits and increased leakage
Solution Approach 1:
An etch stop layer is introduced as an intermediary between the dielectric layer and the contact opening. This etch stop layer selectively prevents the etch process from penetrating through the dielectric layer, thereby avoiding short circuits while still allowing precise contact formation. The etch stop layer acts as a mediator that controls the etch depth and protects underlying structures.
Solution Approach 2:
The etch stop layer is formed on the dielectric layer before the contact etch process is performed. This preliminary action prepares the structure in advance to prevent punch-through during the subsequent etch process, ensuring that the dielectric layer is protected before any damage can occur.
2Ease of operation
If etch process is performed to form contact, then electrical connection is established, but dielectric layer punch through causes harmful effects
Solution Approach 1:
The etch stop layer serves as a protective intermediary that allows the etch process to proceed sufficiently to establish contact connectivity while preventing excessive penetration that would cause short circuits and leakage. It mediates between the need for good electrical connection and the need to prevent harmful punch-through effects.
Solution Approach 2:
The etch stop layer is applied in advance to counteract the potential harmful effect of punch-through. By having this protective layer in place before the etch process, the patent prevents the generation of short circuits and leakage currents that would otherwise occur if the etch penetrated too deeply into the dielectric layer.
Data Source
AI summary
A semiconductor device includes a first conductive feature, a second conductive feature, and a first dielectric layer positioned between the first conductive feature and the second conductive feature. An etch stop layer is over the first dielectric layer. A cap layer is over the first conductive feature, the second conductive feature, and the etch stop layer.