Trilayer Resist Patterning for Higher-Resolution Lithography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor devices shrink, the process windows for photolithographic processing become tighter, leading to challenges in maintaining pattern resolution and transferring photoresist patterns to underlying layers, resulting in defects like bridging lines and footing, which affect the yield and efficiency of device manufacturing.
Innovation Solution
A trilayer resist system is employed, comprising a bottom layer for planarization, a middle layer with a silicon-containing polymer and bound photoacid generator that generates acid upon exposure, and a photosensitive upper layer, which reduces scum defects and allows for lower exposure doses, improving pattern resolution and device yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photolithographic processing is used for pattern formation, then pattern transfer is achieved, but pattern resolution deteriorates due to tighter process windows
Solution Approach 1:
The resist system is divided into three distinct layers: a bottom layer for planarization and adhesion, a middle layer containing silicon-containing polymer and bound photoacid generator for pattern formation, and a top photosensitive layer for exposure. This segmentation allows each layer to perform its specific function optimally, with the bottom layer providing a planar base that improves pattern resolution while the middle layer maintains reliable pattern transfer.
Solution Approach 2:
The bottom layer acts as an intermediary between the substrate and the pattern-forming middle layer. It provides planarization that mediates surface irregularities, thereby improving pattern resolution. The middle layer with bound photoacid generator serves as an intermediary that generates acid in situ during exposure, enabling reliable pattern transfer even with tighter process windows.
2Ease of manufacture
If conventional photolithography is used, then manufacturing process is simple, but defects like bridging lines and footing increase
Solution Approach 1:
By segmenting the resist into three layers with distinct functions, the system eliminates defects that plague conventional single-layer or dual-layer systems. The bottom layer prevents footing by providing a planar base, the middle layer with bound photoacid generator prevents bridging lines through controlled acid generation, and the top layer maintains process simplicity through standard exposure procedures.
Solution Approach 2:
The invention changes the chemical parameters of the resist system by incorporating a silicon-containing polymer with bound photoacid generator in the middle layer. This parameter change enables controlled acid generation during exposure, which prevents bridging lines and footing defects while maintaining ease of manufacture through conventional photolithographic processing.
3Manufacturing precision
If exposure dose is increased to improve pattern transfer, then pattern resolution improves, but manufacturing efficiency decreases
Solution Approach 1:
The bound photoacid generator in the middle layer acts as an intermediary that converts exposure energy into localized acid generation. This intermediary mechanism improves pattern resolution by enabling precise pattern formation at lower exposure doses, thereby maintaining high manufacturing efficiency with increased wafers per hour.
Solution Approach 2:
The invention changes the exposure dose parameter by utilizing the bound photoacid generator system, which requires lower exposure doses to achieve the same pattern resolution as conventional systems. This parameter change directly improves productivity by allowing faster processing while maintaining high pattern resolution.
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 trilayer resist system enhances pattern resolution, decreases line width and edge roughness, and increases the number of wafers that can be processed per hour, thereby improving semiconductor device manufacturing efficiency and yield.
Implementation Method 1
a middle layer with a silicon-containing polymer and bound photoacid generator that generates acid upon exposure
Implementation Method 2
exposed to an energy that has itself been patterned. Such an exposure modifies the chemical and physical properties of the exposed regions of the photosensitive material
Data Source
AI summary
A method of manufacturing a semiconductor device includes forming a first layer including an organic material over a substrate. A second layer including a reaction product of a silicon-containing material and a photoacid generator is formed over the first layer. A photosensitive layer is formed over the second layer, and the second layer is patterned.