Mask Layer Taper Angle Control via Cyclic Deposition and Etching
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Solution Overview
Problem
Existing substrate processing methods face challenges in achieving uniformity of critical dimensions in contact hole patterns, leading to variations in wiring resistance and contact resistance, which affect device performance.
Innovation Solution
A substrate processing method involving a cycle of deposition and removal steps on a patterned mask layer, adjusting the taper angle of the side surface of the mask pattern to a desired range between 85° and 95°, using specific gas combinations and process conditions to improve local critical dimension uniformity (L-CDU) and reduce pattern variation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional deposition and etching steps are used to form contact hole patterns, then the basic pattern structure is achieved, but variation in critical dimensions occurs leading to non-uniform wiring and contact resistance
Solution Approach 1:
The patent applies periodic action by repeating the deposition-etching cycle multiple times to progressively refine the contact hole pattern. Each cycle deposits a thin film layer and then selectively etches it, with the repetition allowing cumulative control over the final pattern geometry and taper angle, thereby reducing critical dimension variation
Solution Approach 2:
The patent utilizes parameter changes by varying deposition thickness, etching time, and gas composition across different cycles to control the taper angle within 85-95 degrees. This precise parameter control ensures uniform critical dimensions and consistent electrical properties throughout the pattern
2Manufacturing precision
If the taper angle of mask pattern side surfaces is not controlled, then the patterning process is simpler, but variation in critical dimensions increases
Solution Approach 1:
The patent implements preliminary action by controlling the taper angle during the patterning process itself through repeated deposition and etching cycles, rather than addressing critical dimension variation in subsequent steps. This preliminary control of geometry prevents downstream variability in critical dimensions
3Manufacturing precision
If repeated deposition and removal steps are performed to control taper angle, then critical dimension uniformity is improved, but processing time increases
Solution Approach 1:
The patent applies partial action by performing repeated deposition and etching cycles only to the extent necessary to achieve the desired taper angle control and critical dimension uniformity. The process is optimized to perform just enough repetitions to obtain L-CDU within specifications without unnecessary additional processing time
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 effectively reduces variation in critical dimensions, enhancing the uniformity of contact holes and improving device performance by controlling the taper angle and repeating the deposition and removal steps to achieve consistent CD sizes.
Implementation Method 1
a) depositing deposits on a patterned mask layer formed over an etching film
Implementation Method 2
a) depositing deposits on a patterned mask layer formed over an etching film
Data Source
AI summary
There is provision of a processing method including a) depositing deposits on a patterned mask layer formed over an etching film; b) removing a part of the mask layer, a part of the deposits, or both the part of the mask layer and the part of the deposits; and c) repeating a) and b) at least once, thereby causing a taper angle of a side surface of a pattern formed in the mask layer to be a desired angle.