Multi-Depth Barrier Contact Structure for Easier Semiconductor Filling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor devices face challenges in forming conductive contacts due to vase-like or oval-shaped contact openings, which can lead to incomplete filling and degrade device performance or yield.
Innovation Solution
A unique fabrication process involving multiple etching-deposition cycles with different barrier layers, where each cycle etches the contact opening and deposits a barrier layer, followed by resputtering to remove the bottom segment, resulting in a staircase-like profile that is easier to fill, and allows for different material compositions to serve various roles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional vase-like or oval-shaped contact opening is formed, then the contact opening can be created using standard fabrication processes, but the filling process becomes difficult and device performance or yield degrades
Solution Approach 1:
The barrier layer is divided into multiple segments at different depths within the contact opening, creating a multi-level structure. This segmentation allows each barrier layer to serve specific functions at different locations, improving the overall filling quality while maintaining ease of manufacture through standardized deposition processes.
Solution Approach 2:
Different barrier layers are positioned at specific depths within the contact opening to provide localized protection and control. The first barrier layer is at a first depth, the second barrier layer is at a second depth, and the third barrier layer is at a third depth, allowing each region to have optimized properties for its specific function.
2Reliability
If multiple barrier layers with different depths are formed using etching-deposition cycles, then the filling process is improved and leakage is prevented, but the fabrication process complexity increases
Solution Approach 1:
The fabrication process uses periodic etching-deposition cycles to form multiple barrier layers at different depths. Each cycle consists of etching the contact opening to a specific depth followed by depositing a barrier layer, repeating this process multiple times to create the multi-level barrier structure. This periodic approach systematically builds the complex structure while maintaining process control.
Solution Approach 2:
The different barrier layers act as intermediaries at various depths within the contact opening, providing gradual protection and control during the filling process. These intermediate barrier layers facilitate the transition from the contact opening to the fill material, improving reliability without requiring overly complex single-step processes.
3Reliability
If barrier layers are deposited to different depths in the contact opening, then different material compositions can serve various roles and improve device performance, but the deposition process requires precise control
Solution Approach 1:
The barrier layer structure is segmented into multiple distinct layers at different depths, each potentially using different material compositions. The first barrier layer, second barrier layer, and third barrier layer can be formed with different materials to serve various functional roles, with each layer's depth precisely controlled through the etching-deposition cycle process.
Solution Approach 2:
The deposition process controls the depth and material composition parameters of each barrier layer independently. By varying the deposition conditions and etching depths in each cycle, the process creates barrier layers with different materials and depths, allowing optimization of device performance while maintaining manufacturing precision through parameter control.
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 improves the filling of contact openings, enhances device performance by preventing leakage and promoting silicide formation, and simplifies the fabrication process by using the same tool for deposition and resputtering.
Implementation Method 1
a deposition process to deposit a respective barrier layer in the etched contact opening
Implementation Method 2
The resputtering process removes a bottom segment of the deposited barrier layer
Data Source
AI summary
A semiconductor device includes a transistor having a source/drain and a gate. The semiconductor device also includes a conductive contact for the transistor. The conductive contact provides electrical connectivity to the source/drain or the gate of the transistor. The conductive contact includes a plurality of barrier layers. The barrier layers have different depths from one another.