Epitaxial Growth Tiles for CMP Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor fabrication processes face challenges in achieving uniformity due to varying pattern densities, particularly in trench CMP and epitaxial growth, where existing methods like reusing dummy features for density matching produce suboptimal results.
Innovation Solution
A tiling strategy is implemented where a first set of tiles is optimized for trench CMP, and a second set is derived for epitaxial growth by removing and reorienting or adjusting the dimensions of tiles, allowing independent control of growth rates and facets, thereby decoupling the needs of trench CMP from epitaxial growth processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pattern density is increased in less populated active regions, then trench CMP uniformity is improved, but epitaxial growth film quality deteriorates
Solution Approach 1:
The patent applies different pattern density configurations to different regions of the semiconductor device. Specifically, it places epitaxial growth tiles in less populated active regions with optimized spacing and density tailored for epitaxial film quality, while maintaining separate trench CMP tiles for density matching. This local differentiation allows each process to have its optimal pattern density in the respective regions, resolving the contradiction between CMP uniformity and film quality.
Solution Approach 2:
The patent changes the pattern density parameters independently for trench CMP and epitaxial growth by using separate tile sets with different configurations. The epitaxial tiles are positioned and sized to optimize film quality parameters, while trench CMP tiles are positioned to optimize CMP uniformity. This parameter differentiation resolves the contradiction by allowing each process to operate at its optimal density regime.
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
This approach effectively compensates for global and local pattern density effects, allowing for tailored silicon overburden and epitaxial CMP characteristics, improving process uniformity and film quality.
Implementation Method 1
when epitaxial growth processes are used to form silicon germanium alloy films on CMOS substrates
Data Source
AI summary
A method for making a semiconductor device is provided which comprises (a) creating a first data set (301) which defines a first set of tiles (303) for a trench chemical mechanical polishing (CMP) process; (b) deriving a first trench CMP mask set (307) and a first epitaxial growth mask set (309) from the first data set, wherein the first epitaxial growth mask set is derived from the first data set by removing a subset (305) of the tiles defined by the first data set and incorporating the subset of tiles into the first epitaxial growth mask set; and (c) reconfiguring the first trench CMP mask set to account for the first epitaxial growth mask set, thereby defining a second trench CMP mask set (308).