Semiconductor Spacer Control for Sub-Lithographic Critical Dimensions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor fabrication techniques face challenges in achieving sub-lithographic features due to physical limitations, particularly in controlling critical dimensions and shapes of semiconductor devices, which affects electrical and physical requirements such as wiring and transistor spacing.
Innovation Solution
A semiconductor device and method involving a mask layer with specific materials and spacers are used, where a blocking pattern is formed below the spacers to control the critical dimension, allowing for precise control of the blocking pattern's size, enabling the formation of smaller dimensions and specific layouts in semiconductor devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional photolithography process is used, then manufacturing process is simple, but critical dimension control becomes insufficient for sub-lithographic features
Solution Approach 1:
The fabrication process is divided into multiple distinct stages: forming sacrificial patterns, depositing spacers, forming blocking patterns, and selective removal. This segmentation allows each stage to be optimized independently for precision while maintaining overall process manageability
Solution Approach 2:
Sacrificial patterns are formed in advance before the actual device features are created. These pre-formed patterns serve as templates that guide subsequent spacer formation and blocking pattern creation, enabling precise critical dimension control before final device fabrication
2Volume of moving object
If device size is reduced to achieve higher integration density, then stacking and integration density increases, but physical limitations of photolithography prevent further miniaturization
Solution Approach 1:
Spacer structures serve as intermediary elements between the sacrificial patterns and the final device features. The spacers are deposited conformally on the sacrificial patterns and then selectively removed, enabling the formation of features smaller than the original sacrificial pattern dimensions
Solution Approach 2:
The process transitions from two-dimensional photolithographic patterning to three-dimensional spacer formation and selective removal. By utilizing vertical spacer deposition and selective etching, the method achieves sub-lithographic lateral dimensions through vertical process control
3Ease of manufacture
If design and process development costs are reduced, then fabrication cost decreases, but achieving sub-lithographic features becomes more difficult
Solution Approach 1:
The method changes key process parameters including material selection for sacrificial patterns and spacers, deposition conditions, and etching selectivity ratios. These parameter changes enable precise feature formation using existing equipment, avoiding the need for expensive new lithography tools
Data Source
AI summary
A semiconductor device and a method of fabricating the same, the semiconductor device includes a hard mask layer and a plurality of spacers. The hard mask layer is disposed on a target layer and has a first material and a second material. The spacers are disposed on the hard mask layer, wherein a first portion of the spacers is disposed on the first material, and a second portion of the spacers is disposed on the second material.