Plasma Etching of Silicon Films With High Selectivity and Mask Protection
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Solution Overview
Problem
Existing etching methods for silicon-containing films face challenges in achieving efficient and selective etching while preserving the integrity of underlying masks, particularly in semiconductor manufacturing processes.
Innovation Solution
An etching method utilizing a plasma processing system that employs a combination of HF gas and PClaFb gas or PCcHdFe gas, along with controlled plasma generation, to etch silicon-containing films while using a mask to protect underlying structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional etching methods are used to increase etching rate, then productivity improves, but mask integrity deteriorates due to excessive mask degradation
Solution Approach 1:
The patent changes the chemical parameters of the etching process by introducing a multi-component gas mixture containing HF, PClaFb, and PCcHdFe. This specific composition enables high etching rates while maintaining mask integrity through controlled chemical reactions that preferentially etch silicon-containing films without attacking the mask material.
Solution Approach 2:
The patent uses a composite processing gas system combining multiple gases (HF, PClaFb, PCcHdFe) that work synergistically. The HF provides fluorine for silicon etching, while the phosphorus-containing compounds provide chlorine for mask protection, creating a composite chemical environment that simultaneously achieves high etching rate and mask preservation.
2Productivity
If aggressive etching conditions are applied to improve etching efficiency, then productivity increases, but manufacturing precision decreases due to reduced selectivity
Solution Approach 1:
The patent optimizes the concentration ratios of gases in the processing mixture, specifically controlling the proportions of HF, PClaFb, and PCcHdFe. This parameter optimization enables the etching process to maintain high efficiency while achieving superior selectivity between silicon-containing films and mask materials through controlled chemical affinity differences.
3Device complexity
If standard processing gases are used to simplify the process, then device complexity is reduced, but productivity decreases due to lower etching rate
Solution Approach 1:
The patent employs a composite gas system combining HF with phosphorus-containing compounds (PClaFb and PCcHdFe). This composite approach, while adding some complexity to the gas mixture, achieves dramatically improved etching rates and selectivity that far outweigh the minor increase in process complexity, delivering high productivity with controlled chemistry.
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 method enhances etching efficiency and selectivity, improving the etching rate of silicon-containing films while minimizing mask degradation and maintaining pattern integrity.
Implementation Method 1
etching the silicon-containing film by generating plasma from a processing gas containing HF gas, and PClaFb gas (each of a and b is an integer of 1 or more) or PCcHdFe gas (each of d and e is an integer of 1 or more, and c is an integer of 0 or more), in the chamber
Data Source
AI summary
An etching method includes: (a) providing a substrate having a silicon-containing film and a mask on the silicon-containing film in a chamber of a plasma processing apparatus, and (b) etching the silicon-containing film by generating plasma from a processing gas containing HF gas, and PClaFb gas (each of a and b is an integer of 1 or more) or PCcHdFe gas (c is an integer of 0 or more, and each of d and e is an integer of 1 or more), in the chamber.