Single-Chamber Wafer Etching for Hard Mask and Etch Stop Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor devices approach smaller feature sizes, the processes used in their manufacturing face challenges such as the need for precise etching and removal of hardmasks and etch stop layers, which can lead to inefficiencies and contamination issues in current multi-step processes.
Innovation Solution
A single-chamber process using selective etchants and rinses to remove both hardmasks and etch stop layers, with controlled dispensing and rotation of the semiconductor device to minimize contamination and increase throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multi-step processes are used to remove hardmasks and etch stop layers, then the etching process can be performed, but contamination risks increase and processing efficiency decreases
Solution Approach 1:
The patent combines multiple etching steps into a single etching chamber, where hardmasks and etch stop layers are removed in sequence without transferring the substrate to another chamber. This merging of processes maintains contamination control while improving processing efficiency by eliminating intermediate handling steps.
Solution Approach 2:
The etching chamber is designed to perform multiple functions: removing hardmasks, removing etch stop layers, and performing intermediate rinsing, all within the same chamber. This multi-functionality resolves the contradiction by allowing sequential operations that maintain cleanliness while improving throughput.
2Productivity
If feature sizes are reduced to increase integration density, then more components can be integrated, but manufacturing precision requirements increase
Solution Approach 1:
The patent employs selective etchants with different chemical compositions and concentrations tailored for specific materials (hardmasks vs. etch stop layers). By changing etching parameters such as chemical composition, temperature, and exposure time between steps, the process achieves high precision removal of each layer type despite reduced feature sizes.
Solution Approach 2:
The hardmask is completely removed before etching the etch stop layer, preparing the surface for subsequent precise etching operations. This preliminary action ensures that each etching step works on a clean, well-defined surface, maintaining manufacturing precision at smaller feature sizes.
3Manufacturing precision
If multiple process steps are performed in separate chambers, then each step can be optimized, but the number of processing steps increases
Solution Approach 1:
The patent merges the hardmask removal step and etch stop layer removal step into a single etching chamber, reducing the total number of process steps while maintaining the ability to optimize each step through selective etching chemistry and controlled processing sequences.
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 allows for more precise control over the etching process, reduces contamination risks, and increases processing efficiency by performing multiple steps within a single apparatus, enhancing the integration density and reliability of semiconductor devices.
Implementation Method 1
rotating the semiconductor device during the dispensing of the first etchant and the dispensing of the second etchant
Implementation Method 2
applying a first etchant to remove the hard mask layer
Implementation Method 3
applying a second etchant to remove a portion of the etch stop layer
Implementation Method 4
rinsing the semiconductor device between the dispensing the first etchant and the dispensing of the second etchant
Data Source
AI summary
An apparatus, semiconductor device and method of manufacture are presented, wherein a hard mask layer and one or more etch stop layers are etched in an etching chamber. In an embodiment the semiconductor device is placed on a mounting platform at a first height and an etch process is performed, then the semiconductor device is moved to a second height within the chamber and a second etch process is performed, with the rotational speed of the semiconductor device reduced during movements in order to reduce the chance of cross contamination.