Selective Mask Protection Deposition for High-Aspect Ratio Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing etch mask protection methods suffer from mask loss during etching processes, leading to degraded etch profile and reduced uniformity, which affects the yield of microelectronic device fabrication, especially in high-aspect ratio etches.
Innovation Solution
A method involving non-plasma vapor and halide treatments is used to selectively deposit a mask protection material on the etch mask, utilizing non-plasma vapor treatment to form a first component and non-plasma halide gas treatment to form a second component, enhancing selectivity and etch resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If carbon deposition is used to protect the mask during etching, then mask protection is improved, but deposition occurs on all surfaces including the etch target material, working against the etching process
Solution Approach 1:
The invention applies selective deposition to deposit mask protection material only on specific surfaces (mask sidewalls and top surface) while avoiding deposition on the etch target material. This is achieved by controlling deposition conditions such that the mask protection material is deposited locally where needed without interfering with the etching process on the target material surfaces.
2Reliability
If mask thickness is increased to reduce mask loss, then mask protection is improved, but patterning capabilities and attainable aspect ratio and critical dimension are degraded
Solution Approach 1:
The invention deposits mask protection material before the etching process begins, creating a protective layer on the mask sidewalls and top surface in advance. This preliminary deposition provides mask protection without requiring increased mask thickness, thereby preserving the mask's patterning capabilities and critical dimension precision.
3Reliability
If different mask material is used to combat mask loss, then mask protection is improved, but process complexity and cost increase
Solution Approach 1:
The invention creates a composite structure by depositing mask protection material (such as silicon oxide or silicon nitride) over the existing mask material (such as photoresist or hard mask). This composite approach provides enhanced mask protection while maintaining compatibility with standard mask materials and processes, avoiding the need to switch to more complex or expensive alternative mask materials.
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 improves etch selectivity and resistance, reducing mask loss and maintaining uniformity during etching processes, particularly in fluorine- and hydrogen-rich environments, benefiting high-aspect ratio etches.
Implementation Method 1
a non-plasma vapor treatment including treating a mask having openings exposing an underlying layer with a non-plasma vapor to selectively deposit a first component of a mask protection material on the mask
Implementation Method 2
a non-plasma halide treatment including treating the mask and the underlying layer with a non-plasma halide gas to selectively deposit a second component of a mask protection material on the mask
Data Source
AI summary
A method for selectively depositing a mask protection material using non-plasma treatments includes performing a non-plasma vapor treatment and performing a non-plasma halide treatment. During the non-plasma vapor treatment, a mask having openings exposing an underlying layer is treated with a non-plasma vapor to selectively deposit a first component of a mask protection material on the mask. During the non-plasma halide treatment, the mask and the underlying layer are treated with a non-plasma halide gas to selectively deposit a second component of the mask protection material on the mask. The non-plasma treatments are performed sequentially, but may be performed in either order. An optional pretreatment may be performed prior to the non-plasma treatments during which the mask is pretreated to form a reactive surface.