Semiconductor Contact Plug Fabrication via Dual Wet Clean
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The yield of contact plugs with high aspect ratio in semiconductor devices is low due to limitations in the back end of the line (BEOL) process capacity, and the formation of a barrier layer between upper and lower contact structures complicates the fabrication process and affects conductivity.
Innovation Solution
A method involving two separate wet clean processes using different cleaning agents is employed, where a first cleaning agent comprising Tetrakis(ethylmethylamino)hafnium (TEMAH) and H2O2 is used followed by a second cleaning agent of deionized water with carbon dioxide gas, to improve the interconnection structure formation and reduce tungsten loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a barrier layer is formed between upper and lower contact structures, then the fabrication process complexity increases, but the conductivity of the contact is affected
Solution Approach 1:
The invention removes the barrier layer that was traditionally formed between upper and lower contact structures. By extracting this unnecessary layer, the fabrication process becomes simpler and the contact conductivity is improved without compromising structural integrity.
2Device complexity
If conventional single cleaning agent is used, then the cleaning process is simple, but tungsten loss occurs and M0CT interface quality deteriorates
Solution Approach 1:
The cleaning process is divided into two sequential stages using different cleaning agents. The first cleaning agent removes organic contaminants, while the second cleaning agent removes inorganic contaminants. This segmentation of the cleaning function improves M0CT interface quality and prevents tungsten loss without excessive complexity.
3Productivity
If BEOL process capacity is increased to improve contact plug yield, then the fabrication complexity increases, but the yield of high aspect ratio contact plugs remains low
Solution Approach 1:
The invention changes the chemical parameters of the cleaning process by introducing two different cleaning agents with distinct chemical properties. This parameter change in the cleaning chemistry improves contact plug yield by preventing tungsten loss and improving interface quality, without requiring increased BEOL process capacity.
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 enhances the yield and reduces fabrication complexity by preventing tungsten loss and improving the M0CT interface, thereby improving the overall semiconductor device fabrication process.
Implementation Method 1
utilizing a first cleaning agent for performing a first wet clean process
Implementation Method 2
a first cleaning agent comprising Tetrakis(ethylmethylamino)hafnium (TEMAH) and H2O2
Implementation Method 3
utilizing a second cleaning agent for performing a second wet clean process
Implementation Method 4
a second cleaning agent of deionized water with carbon dioxide gas
Data Source
AI summary
A method for fabricating semiconductor device is disclosed. The method includes the steps of: providing a substrate having an interlayer dielectric (ILD) layer thereon, wherein at least one metal gate is formed in the ILD layer and at least one source/drain region is adjacent to two sides of the metal gate; forming a first dielectric layer on the ILD layer; forming a second dielectric layer on the first dielectric layer; performing a first etching process to partially remove the second dielectric layer; utilizing a first cleaning agent for performing a first wet clean process; performing a second etching process to partially remove the first dielectric layer; and utilizing a second cleaning agent for performing a second wet clean process, wherein the first cleaning agent is different from the second cleaning agent.