Semiconductor Device Structure Self-Aligned Source Drain Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The replacement gate process in CMOS device manufacturing is complex, costly, and difficult to integrate contact holes and high-k dielectric/metal gate stacks, especially for technology nodes below 45 nanometers.
Innovation Solution
A method for manufacturing a semiconductor device structure where source/drain regions are formed in a self-aligned manner before the channel region and gate stack, eliminating the need for a sacrificial gate, and incorporating an inner sidewall spacer to reduce feature size and enhance carrier mobility, while being compatible with high-k dielectric/metal gate processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the replacement gate process is used to avoid adverse influence on gate stack during high temperature annealing, then the gate stack integrity is improved, but the manufacturing process complexity increases and cost increases
Solution Approach 1:
The source/drain regions are formed in advance before the gate stack is created. By performing source/drain implantation and annealing prior to gate stack formation, the harmful high-temperature processing is completed before the gate stack exists, thus protecting the gate stack from thermal damage while avoiding the complexity of replacement gate processes
Solution Approach 2:
The conventional sequence is inverted: instead of forming the gate first and then the source/drain regions (which risks gate damage), the source/drain regions are formed first and the gate stack is formed afterward. This reverse sequencing achieves the same protective effect as replacement gate but with simpler process integration
2Reliability
If the replacement gate process is used to protect gate stack, then the gate stack integrity is improved, but the contact hole integration difficulty increases
Solution Approach 1:
Source/drain regions are formed in advance before gate stack formation, allowing contact hole alignment to be established on well-defined source/drain structures. This preliminary formation of source/drain regions provides stable reference structures for subsequent contact hole patterning, simplifying integration
Solution Approach 2:
The self-aligned formation of source/drain regions creates inherent structural references that automatically guide subsequent processing steps including contact hole formation. The process uses its own generated structures as alignment guides, eliminating the need for separate alignment procedures
3Reliability
If the replacement gate process is used to avoid thermal damage, then the gate stack integrity is improved, but the high-k dielectric/metal gate stack process integration becomes harder
Solution Approach 1:
Source/drain regions are formed before gate stack formation, separating the high-temperature annealing step from the gate stack structure. This timing separation allows high-k dielectric and metal gate materials to be deposited and processed under optimal conditions without exposure to damaging thermal cycles
Solution Approach 2:
The process timing parameter is changed: source/drain formation is moved to occur before gate stack formation rather than after. This parameter change enables the gate stack to be formed with high-k dielectric and metal materials using low-temperature processes, improving compatibility with advanced gate structures
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 simplifies the manufacturing process, reduces costs, avoids impurity diffusion, enhances MOSFET performance by increasing carrier mobility, and improves isolation between gate electrodes, making it compatible with advanced CMOS technology nodes.
Implementation Method 1
performing a source/drain implantation on the semiconductor substrate
Data Source
AI summary
The present invention presents a method for manufacturing a semiconductor device structure as well as the semiconductor device structure. Said method comprises: providing a semiconductor substrate; forming a first insulating layer on the semiconductor substrate; forming a shallow trench isolation embedded in the first insulating layer and the semiconductor substrate; forming a channel region embedded in the semiconductor substrate; and forming a gate stack stripe on the channel region. Said method further comprises, before forming the channel region, performing a source/drain implantation on the semiconductor substrate. By means of forming the source/drain regions in a self-aligned manner before forming the channel region and the gate stack, said method achieves the advantageous effects of the replacement gate process without using a dummy gate, thereby simplifying the process and reducing the cost.