CO2 Etching Tri-Layer Mask for Semiconductor Pattern Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional etching processes in semiconductor devices face challenges such as boron penetration and depletion effects, leading to inferior performance and reduced gate capacitance due to the scaling down of device sizes, which affects the accuracy and efficiency of the etching process.
Innovation Solution
A tri-layer structure comprising an organic layer, a bottom anti-reflection coating (BARC), and a photoresist layer is used on a substrate with defined regions, where the BARC and photoresist layers act as masks for an etching process using CO2 as an etchant to achieve precise pattern formation and improve etching accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If conventional poly-silicon gate is used in scaling down semiconductor devices, then device size can be reduced, but performance deteriorates due to boron penetration and depletion effect
Solution Approach 1:
The patent changes the material parameter of the gate electrode from conventional poly-silicon to organic semiconductor materials, which have different electrical and chemical properties that eliminate boron penetration and depletion effects while enabling continued device scaling
Solution Approach 2:
The patent employs a composite structure consisting of multiple organic layers (organic layer, BARC layer, and photoresist layer) that work together to achieve both miniaturization and maintained performance through their combined functional properties
2Productivity
If two-exposure-two-etching (2P2E) or two-exposure-one-etching (2P1E) process is used, then contact and metal interconnect can be formed, but etching accuracy is insufficient for small size structures
Solution Approach 1:
The patent segments the etching process into multiple selective etching steps, each targeting specific layers (organic layer, BARC layer) with different etchants and parameters, thereby achieving high precision pattern transfer for small size structures
Solution Approach 2:
The patent introduces an intermediate organic layer that serves as a sacrificial mask and etching target, enabling precise control of the etching process and accurate pattern formation in small size semiconductor structures
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 described etching process enhances the accuracy and precision of pattern formation, overcoming the limitations of conventional etching technologies by allowing for the formation of desired layers with improved accuracy and reducing the formation of unwanted micro trenches.
Implementation Method 1
An etching process is performed to remove the organic layer in the second region by using the BARC and/or the photoresist layer as a mask, wherein the etching process uses an etchant comprises CO2
Data Source
AI summary
A method of performing an etching process is provided. A substrate is provided, wherein a first region and a second region are defined on the substrate, and an overlapping region of the first region and the second region is defined as a third region. A tri-layer structure comprising an organic layer, a bottom anti-reflection coating (BARC), and a photoresist layer is formed on the substrate. The photoresist layer and the BARC in the second region are removed. An etching process is performed to remove the organic layer in the second region by using the BARC and/or the photoresist layer as a mask, wherein the etching process uses an etchant comprises CO2.