Wafer Back Side Protection Layer for Semiconductor Manufacturing
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Solution Overview
Problem
The semiconductor manufacturing process faces challenges in protecting the back side of a semiconductor wafer from damage during photoresist removal and chuck mark formation, leading to uneven surfaces and increased fabrication costs due to the need for grinding processes.
Innovation Solution
A protection layer is formed on the back side of the semiconductor substrate using a plasma process, which provides a planar surface and prevents etching during subsequent wet cleaning processes, thereby avoiding chuck marks and reducing fabrication time and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photoresist removal process is performed on front side of wafer, then pattern features are obtained, but back side of wafer is damaged
Solution Approach 1:
A protection layer is deposited on the back side of the wafer to serve as an intermediary barrier. This protection layer prevents direct contact between the wafer back side and harmful factors during photoresist removal and cleaning processes, while allowing the front side processing to proceed normally.
Solution Approach 2:
The protection layer is formed on the back side of the wafer before the photoresist removal process begins. This preliminary protective measure ensures that when subsequent cleaning and etching processes are performed, the back side is already protected, preventing damage before it can occur.
2Ease of operation
If wet cleaning process is performed to remove photoresist, then cleaning is achieved, but chuck marks are formed on back side
Solution Approach 1:
The protection layer acts as an intermediary between the wet cleaning process and the wafer back side. It allows the cleaning chemistry to work effectively on the front side while preventing direct contact between the cleaning solution/chuck and the wafer back side surface, thus avoiding chuck marks.
Solution Approach 2:
The protection layer provides beforehand cushioning by creating a sacrificial barrier that absorbs the harmful effects of the wet cleaning process and chuck contact. Any potential damage is inflicted on the protection layer rather than the wafer back side, preserving the original surface quality.
3Manufacturing precision
If grinding process is used to repair back side damage, then surface flatness is improved, but fabrication time and cost increase
Solution Approach 1:
The protection layer is formed in advance before any damage can occur to the wafer back side. By preventing damage proactively through the deposition of a protective film, the need for subsequent time-consuming grinding and repair processes is eliminated, maintaining high fabrication efficiency.
Solution Approach 2:
The protection layer converts the potentially harmful wet cleaning and chuck contact processes into beneficial operations. The same processes that could cause damage are transformed into safe operations by the presence of the protection layer, eliminating the need for corrective grinding while maintaining surface quality.
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 protection layer effectively prevents damage to the back side of the wafer during cleaning, maintains a planar surface, and reduces the need for costly grinding processes, thereby enhancing the manufacturing efficiency and reducing costs.
Implementation Method 1
A protection layer is formed on the back side of the semiconductor substrate using a plasma process
Data Source
AI summary
Embodiments of mechanisms of forming a semiconductor device structure are provided. The semiconductor device structure is provided. The semiconductor device structure includes a substrate having a front side and a back side. The semiconductor device structure also includes devices formed on the front side of the substrate and interconnect structures formed on the devices. The semiconductor device structure further includes a protection layer formed on the back side of the substrate, and the protection layer has a thickness over about 10 A.