HF Plasma Etching of Silicon Films With Reaction Gas Control
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Solution Overview
Problem
Existing etching methods for silicon-containing films using masks with amorphous carbon or organic polymers result in feature failures.
Innovation Solution
An etching method using a plasma processing apparatus with alternating plasma generated from first and second process gases, where the first gas includes hydrogen fluoride and a reaction control gas, and the second gas includes hydrogen fluoride with varying partial pressures of reaction accelerator or inhibitor gases, to control the etching process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If existing etching methods using hydrogen fluoride gas are employed, then etching of silicon-containing films can be performed, but feature failures occur due to uncontrolled reactions
Solution Approach 1:
The patent introduces reaction control gases (accelerator gases like NF3, PF5, PCl3 and inhibitor gases like BCl3, SiCl4) as intermediaries to mediate the reaction between hydrogen fluoride and silicon-containing films. These control gases regulate the etching reaction rate and selectivity, preventing uncontrolled reactions that cause feature failures while maintaining effective etching of the silicon-containing film.
2Manufacturing precision
If reaction control gases are added to control the etching reaction, then etching precision is improved, but process complexity increases
Solution Approach 1:
The patent controls the etching process by adjusting gas composition parameters, including the types and partial pressures of reaction control gases. By varying these parameters, the etching rate, selectivity, and reaction control can be optimized without fundamentally changing the etching apparatus or process architecture, thus managing complexity while achieving precision.
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
Reduces feature failures in etching silicon-containing films by optimizing the etching process with controlled reaction gases, enhancing precision and reliability.
Implementation Method 1
etching the silicon-containing film using plasma generated from a first process gas
Implementation Method 2
reaction between hydrogen fluoride and the silicon-containing film
Data Source
AI summary
An etching method comprises (a) providing a substrate in a chamber, the substrate including a silicon-containing film and a mask on the silicon-containing film; and (b) etching the silicon-containing film, including (b-1) etching the silicon-containing film using plasma generated from a first process gas, the first process gas containing a hydrogen fluoride gas and a reaction control gas to control a reaction between hydrogen fluoride and the silicon-containing film, the first process gas containing, as the reaction control gas, at least one of a reaction accelerator gas to accelerate the reaction or a reaction inhibitor gas to inhibit the reaction, and (b-2) etching the silicon-containing film using plasma generated from a second process gas, the second process gas containing a hydrogen fluoride gas, and containing at least one of a reaction accelerator gas to accelerate the reaction or a reaction inhibitor gas to inhibit the reaction.