Aluminum Etching Stop Layer for Platinum Patterning
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Solution Overview
Problem
Current etching processes for patterning platinum in semiconductor fabrication lack control, leading to non-uniformity and loss of the dielectric layer underneath.
Innovation Solution
A method involving the use of an aluminum layer as an etching stop layer, where a platinum layer is formed on top of the aluminum layer, and sequential etching processes are performed to pattern both layers while minimizing dielectric layer loss, using Cl2 and BCl3 gases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If current etching process is used for patterning platinum, then platinum pattern can be formed, but the etching process cannot be controlled effectively leading to non-uniformity and loss of dielectric layer
Solution Approach 1:
An aluminum layer is introduced as an intermediary etching stop layer between the platinum layer and the dielectric layer. This aluminum layer serves as a mediator that protects the dielectric layer from direct etching while enabling controlled platinum patterning. The aluminum layer is selectively removed after platinum patterning is complete, revealing the underlying dielectric layer without damage.
2Ease of manufacture
If etching process is performed on platinum layer, then platinum pattern is formed, but dielectric layer underneath is lost due to lack of etching stop control
Solution Approach 1:
The aluminum layer is formed on the dielectric layer before the platinum layer is deposited and patterned. This preliminary action creates a protective barrier that prevents dielectric layer loss during the subsequent platinum etching process. The aluminum layer is removed after platinum patterning is complete, revealing the intact dielectric layer.
3Manufacturing precision
If aluminum layer is used as etching stop layer, then etching control is improved and dielectric layer loss is reduced, but process complexity increases due to additional layers and steps
Solution Approach 1:
The etching process utilizes parameter changes by employing different etching gases (Cl2 for platinum, BCl3 for aluminum) and controlling etching conditions to achieve selective removal of materials. The aluminum layer thickness and platinum layer thickness are optimized parameters that enable effective etching control while managing process complexity.
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 uniformity and precision of the patterning process, reducing dielectric layer loss and allowing for accurate pattern formation suitable for various sensor applications.
Implementation Method 1
forming an aluminum layer on the dielectric layer; performing a first etching process to remove part of the platinum layer and part of the aluminum layer for forming a patterned platinum layer; and performing a second etching process to remove part of the aluminum layer exposed by the patterned platinum layer and part of the dielectric layer
Implementation Method 2
performing a first etching process to remove part of the platinum layer and part of the aluminum layer
Implementation Method 3
performing a second etching process to remove part of the aluminum layer exposed by the patterned platinum layer and part of the dielectric layer
Data Source
AI summary
A method for fabricating semiconductor device is disclosed. The method includes the steps of: providing a substrate having a dielectric layer; forming an aluminum layer on the dielectric layer; forming a platinum layer on the aluminum layer; performing a first etching process to remove part of the platinum layer and part of the aluminum layer for forming a patterned platinum layer; and performing a second etching process to remove part of the aluminum layer exposed by the patterned platinum layer and part of the dielectric layer.