Capping Layer for Vertical Spacer Profiles in SAMP
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Self-aligned multiple patterning (SAMP) processes in microelectronic workpieces often result in angled spacer profiles due to core material loss during spacer deposition and etch processes, leading to increased pattern variation and degradation in device performance, particularly in FinFET devices.
Innovation Solution
Applying a capping layer over cores prior to spacer formation using a plasma process to minimize core material loss and achieve a more vertical spacer profile, with a target angle of 80-90 degrees for vertical sidewalls, thereby reducing pattern variation and improving device performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If cores are used to form spacers in SAMP processes without additional protective layers, then the process is simpler and requires fewer steps, but core material loss occurs during spacer deposition and etch processes leading to angled spacer profiles and increased pattern variation
Solution Approach 1:
A capping layer is deposited over the cores before spacer formation to protect the core material from loss during subsequent spacer deposition and etch processes. This preliminary protective action prevents corner rounding and material loss, ensuring vertical spacer profiles without complicating the overall process flow.
Solution Approach 2:
The capping layer acts as an intermediary protective layer between the core material and the spacer deposition/etch processes. This intermediate layer prevents direct interaction that would cause material loss, while being removable afterward to leave clean vertical spacer profiles.
2Manufacturing precision
If a capping layer is applied over cores prior to spacer formation, then core material loss is reduced and vertical spacer profiles are achieved, but the process complexity increases with an additional deposition step
Solution Approach 1:
The capping layer is deposited as a preliminary protective measure before spacer formation, preventing core material loss and ensuring vertical profiles. This single additional step is integrated into the existing SAMP process flow, minimizing overall complexity while achieving the desired precision.
Solution Approach 2:
The capping layer modifies the surface parameters of the core (adding a protective coating with different etch selectivity), which changes how the subsequent spacer deposition and etch processes interact with the core structure, enabling vertical profile formation without excessive process complexity.
3Productivity
If cores are removed after spacer formation without protective capping, then the process is faster with fewer steps, but corner loss and material degradation occur leading to pattern variation
Solution Approach 1:
The capping layer is applied in advance to protect core corners and material during the spacer formation process. This preliminary protection prevents the corner loss and material degradation that would otherwise occur, ensuring pattern consistency while maintaining efficient process speed.
Solution Approach 2:
The capping layer provides beforehand cushioning or protection to the core structure against the harsh conditions of spacer deposition and etch processes. This prior cushioning prevents damage before it occurs, ensuring reliable pattern transfer without sacrificing process efficiency.
4Device complexity
If angled spacer profiles are accepted from conventional SAMP processes, then fewer process steps are required, but pattern variation increases and device performance degrades
Solution Approach 1:
The capping layer is deposited as a preliminary protective measure that enables vertical spacer profile formation. This additional step is traded against the acceptance of angled profiles, resolving the contradiction by showing that the small increase in process steps yields significant improvement in pattern precision and device performance.
Solution Approach 2:
The capping layer changes the physical parameters of the core structure (adding a protective coating), which fundamentally alters the outcome of spacer deposition and etch processes from angled to vertical profiles. This parameter change resolves the contradiction between process simplicity and pattern 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
The capping layer reduces material loss during spacer deposition and etch processes, resulting in more vertical spacer profiles and increased spacer height, which minimizes pattern variation and enhances the performance of subsequent pattern transfer steps in microelectronic devices.
Implementation Method 1
Applying a capping layer over cores prior to spacer formation using a plasma process to minimize core material loss
Implementation Method 2
etching the spacer layer to leave spacers adjacent the cores
Data Source
AI summary
Embodiments are described herein that apply capping layers to cores prior to spacer formation in self-aligned multiple patterning (SAMP) processes to achieve vertical spacer profiles. For one embodiment, a plasma process is used to deposit a capping layer on cores, and this capping layer causes resulting core profiles to have protective caps. These protective caps formed with the additional capping layer help to reduce or minimize material loss and corner loss of the core material during spacer deposition and spacer etch processes. This reduction in core material loss improves the resulting spacer profile so that a more vertical profile is achieved. For one embodiment, an angle of 80-90 degrees is achieved for vertical sidewalls of the spacers adjacent core sites with respect to the horizontal surface of the underlying layer, such as a hard mask layer formed on a substrate for a microelectronic workpiece.