Semiconductor Gate Stack Protection Layers for Contact Etching
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Solution Overview
Problem
Existing semiconductor manufacturing processes are inadequate for device scaling-down, particularly in forming semiconductor device structures with precise control over gate stacks and spacer layers, leading to issues with gate electrode shorts and reduced yield.
Innovation Solution
A method involving the formation of protection layers over gate stacks and spacer layers before contact hole etching, using metal compound materials that react with silicon to create a silicide layer, preventing gate electrode shorts and improving yield by controlling the etching process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional etching processes are used without protection layers, then the manufacturing process is simpler and faster, but gate electrode shorts occur and yield decreases
Solution Approach 1:
The patent applies preliminary action by forming protection layers (nitride and oxide layers) over the gate stack and spacer layer before performing the contact hole etching process. This preliminary protective measure prevents gate electrode shorts during etching, thereby improving yield without significantly complicating the overall manufacturing flow.
Solution Approach 2:
The patent uses protection layers as intermediary elements between the etching process and the gate stack/spacer layer. These intermediary layers (particularly the nitride layer) act as barriers that prevent direct contact between the etchant and the underlying structures, preventing shorts while allowing the etching process to proceed.
2Reliability
If protection layers are formed before contact hole etching, then gate electrode shorts are prevented and yield improves, but the manufacturing process becomes more complex
Solution Approach 1:
The protection layers are formed in advance before the contact hole etching step, establishing a protective barrier that simplifies the etching process itself by preventing shorts. Although additional steps are added, the overall ease of manufacture is maintained because the protection layers use standard materials and processes already present in semiconductor fabrication.
Solution Approach 2:
The patent modifies the process parameters by introducing protection layers with specific material compositions (nitride and oxide) and thicknesses. These parameter changes enable the etching process to proceed with better control and reduced risk of shorts, improving ease of manufacture despite the additional steps.
3Area of moving object
If device scaling-down continues with existing processes, then device density increases, but manufacturing precision deteriorates leading to gate electrode shorts
Solution Approach 1:
The patent employs a multi-layer protection structure (nitride and oxide layers) that provides enhanced precision control during the etching process. This protective architecture enables accurate formation of contact holes at scaled dimensions by preventing uncontrolled etching that would lead to gate electrode shorts.
Solution Approach 2:
The patent uses composite protection structures combining different materials (nitride layer and oxide layer) with complementary properties. The nitride layer provides etch resistance while the oxide layer provides additional protection and interface control, together enabling precise manufacturing at scaled dimensions.
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 effectively prevents gate electrode shorts and enhances the yield of semiconductor device structures by ensuring precise control over the etching process and protecting critical layers, thereby improving the reliability of semiconductor devices.
Implementation Method 1
using metal compound materials that react with silicon to create a silicide layer
Data Source
AI summary
A method for forming a semiconductor device structure is provided. The method includes forming a gate stack, a spacer layer, and a dielectric layer over a substrate. The method includes removing a first portion of the dielectric layer to form a first hole in the dielectric layer. A second portion of the dielectric layer is under the first hole. The method includes forming a first protection layer over the gate stack and the spacer layer. The method includes forming a second protection layer over the first protection layer. The second protection layer includes a metal compound material, and the first protection layer and the second protection layer includes a same metal element. The method includes removing the second portion of the dielectric layer to form a through hole. The method includes forming a conductive contact structure in the through hole.