Gate Stack Recess Structure to Preserve Effective Channel Length
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Solution Overview
Problem
The traditional reoxidation process to repair etching damage in gate stack structures of semiconductor devices results in a decrease of the effective channel length, affecting device reliability and performance.
Innovation Solution
The method involves forming a gate insulating and material layer, followed by an etching process that recesses the ends of the gate insulating layer inward relative to the gate layer ends, ensuring the gate layer protrudes, thus allowing the reoxidation process to form an oxidation layer without covering the insulating layer, maintaining the channel length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a reoxidation process is performed after etching to repair damage to the gate stack structure, then the damage to the substrate surface and side surfaces is repaired, but the effective channel length is decreased
Solution Approach 1:
The gate insulating layer is formed with recessed ends before the reoxidation process. This preliminary structural preparation ensures that when reoxidation occurs, the oxidation is confined to the gate layer ends and cannot extend into the channel region, thus protecting the effective channel length while still allowing damage repair to proceed
Solution Approach 2:
The gate insulating layer is designed with different geometries at its ends compared to its middle section. The recessed ends create localized regions where oxidation can occur without affecting the channel, while the main body of the gate insulating layer maintains its full extent to preserve the effective channel length
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 approach prevents the reduction of the effective channel length, enhancing the stability and reliability of the semiconductor device by ensuring the gate layer's oxidation does not diminish the intended channel length.
Implementation Method 1
An etching process is performed on the gate material layer and the gate insulating material layer to form a gate layer and a gate insulating layer
Implementation Method 2
the traditional practice is to perform a reoxidation process after the etching process
Data Source
AI summary
Disclosed is a method for manufacturing a semiconductor device. The method includes: forming a gate insulating material layer on a substrate; forming a gate material layer on the gate insulating material layer; and performing an etching process on the gate material layer and the gate insulating material layer to form a gate layer and a gate insulating layer. The gate insulating layer and the gate layer each include a first end and a second end opposite to each other in a direction parallel to a channel length. The first end of the gate insulating layer is recessed inwards by a preset length relative to the first end of the gate layer, and the second end of the gate insulating layer is recessed inwards by the preset length relative to the second end of the gate layer.