High-K Metal Gate Electrode Structures With Early Cap Layer Adaptation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional approaches to fabricating high-k metal gate electrode structures in integrated circuits face challenges such as process non-uniformities and yield losses due to material erosion during the manufacturing process, particularly when forming gate electrode structures with strain-inducing semiconductor alloys.
Innovation Solution
The technique involves selectively reducing the thickness of the dielectric cap material in an early manufacturing stage to compensate for asymmetric material erosion, allowing for more uniform processing and reducing the risk of gate failures by ensuring similar thickness of dielectric cap materials across different transistor types, thereby enabling the formation of sophisticated high-k metal gate electrode structures with embedded strain-inducing semiconductor alloys.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the dielectric cap material thickness is not selectively reduced, then the manufacturing process is simpler, but material erosion causes non-uniform processing and yield losses
Solution Approach 1:
The patent applies preliminary action by selectively reducing the dielectric cap material thickness in an early manufacturing stage before other processing steps. This anticipates the asymmetric material erosion that will occur during subsequent processing, particularly when forming gate electrode structures with strain-inducing semiconductor alloys. By pre-adjusting the thickness, the patent ensures uniform final thickness across different transistor types, eliminating the need for complex compensatory measures later in the process.
2Reliability
If selective thickness reduction is performed, then material erosion is reduced and yield losses minimized, but additional processing steps are required
Solution Approach 1:
The patent performs the thickness reduction action in advance, before gate electrode structure formation and other processing steps that cause material erosion. This preliminary adjustment ensures that all subsequent processing results in uniform final thickness, improving reliability by preventing gate failures while avoiding the need for multiple corrective processing steps later.
Solution Approach 2:
The patent applies local quality by selectively reducing dielectric cap material thickness only in specific regions where strain-inducing semiconductor alloys will be formed. Different transistor types (e.g., PMOS vs. NMOS) receive different thickness adjustments based on their specific processing requirements, ensuring each region has the optimal starting thickness for its intended processing path.
3Manufacturing precision
If asymmetric material erosion is not compensated, then the manufacturing process is faster, but process non-uniformities occur leading to yield losses
Solution Approach 1:
The patent implements preliminary action by performing selective thickness reduction before other manufacturing steps. This early intervention compensates for anticipated asymmetric material erosion, ensuring uniform processing conditions throughout subsequent steps. The time investment for this single preliminary step is far less than multiple corrective steps that would be needed if erosion compensation were delayed or omitted.
Data Source
AI summary
When forming high-k metal gate electrode structures in transistors of different conductivity type while also incorporating an embedded strain-inducing semiconductor alloy selectively in one type of transistor, superior process uniformity may be accomplished by selectively reducing the thickness of a dielectric cap material of a gate layer stack above the active region of transistors which do not receive the strain-inducing semiconductor alloy. In this case, superior confinement and thus integrity of sensitive gate materials may be accomplished in process strategies in which the sophisticated high-k metal gate electrode structures are formed in an early manufacturing stage, while, in a replacement gate approach, superior process uniformity is achieved upon exposing the surface of a placeholder electrode material.