Reducing Side Etching in Semiconductor Mask Blanks
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Summary
Problems
In the manufacturing of semiconductor devices, the miniaturization of mask patterns and the use of short-wavelength exposure light sources pose challenges in achieving high pattern accuracy and preventing pattern collapse due to side etching during dry etching processes, particularly with chromium-based etching stopper films when using chlorine-based gases and oxygen.
Innovation solutions
A mask blank structure with an etching stopper film made of chromium, oxygen, and carbon, where the chromium content is 50 atomic % or more, and a pattern-forming thin film made of silicon or tantalum, optimized to reduce side etching by controlling the chemical bonding state and using specific etching gases and bias conditions.
TRIZ Analysis
Specific contradictions:
General conflict description:
Principle concept:
If a chromium-based etching stopper film is used with chlorine-based gases and oxygen in dry etching, then etching performance is improved, but side etching increases causing pattern collapse
Why choose this principle:
The patent changes the chemical composition parameters of the etching stopper film by incorporating carbon along with chromium and oxygen. This compositional parameter change modifies the film's chemical reactivity toward chlorine-based etching gases, reducing side etching while maintaining vertical etching performance.
Principle concept:
If a chromium-based etching stopper film is used with chlorine-based gases and oxygen in dry etching, then etching performance is improved, but side etching increases causing pattern collapse
Why choose this principle:
The patent creates a composite etching stopper film material consisting of chromium, oxygen, and carbon. This composite material combines the beneficial properties of each element: chromium provides etch selectivity, oxygen enhances film stability, and carbon reduces side etching by modifying chemical bonding characteristics.
Application Domain
Data Source
AI summary:
A mask blank structure with an etching stopper film made of chromium, oxygen, and carbon, where the chromium content is 50 atomic % or more, and a pattern-forming thin film made of silicon or tantalum, optimized to reduce side etching by controlling the chemical bonding state and using specific etching gases and bias conditions.
Abstract
In the present disclosure, an etching stopper film, a light shielding film comprising a material containing one or more elements selected from silicon and tantalum, and a hard mask film are laminated in that order on a transparent substrate. The etching stopper film is made of a material containing chromium, oxygen and carbon, the chromium content is 50 atomic % or more, the maximum peak in N1s narrow spectrum obtained by means of analysis using X-Ray photoelectron spectroscopy is below the detection limit, and Cr2p narrow spectrum obtained by means of analysis using X-Ray photoelectron spectroscopy has a maximum peak at a binding energy of 574 eV or less.