Tapered Mandrel Patterning for Uniform High-Density Transfer
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Solution Overview
Problem
In semiconductor manufacturing, the adhesion performance between the oxide layer and the mandrel is reduced due to gas generation or material stress differences, leading to uneven pattern transfer during the deposition process, which affects the density and uniformity of the pattern formed.
Innovation Solution
A method involving a substrate with a hard mask layer, a sacrificial layer, and photoresists, where the sacrificial layer is etched to form a mandrel with a decreasing cross-sectional size from top to bottom, allowing an isolation layer to be deposited uniformly and increasing the aspect ratio, thereby preventing gaps and ensuring accurate and uniform pattern transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If an oxide layer is deposited on a mandrel by atomic deposition process, then the pattern density is increased, but gaps are generated between the oxide layer and the mandrel due to gas generation or material stress differences
Solution Approach 1:
The mandrel is designed with a tapered structure where the cross-sectional size gradually decreases from the top end to the bottom end. This creates local geometric variation that compensates for the uniform gap formation during oxide layer deposition, ensuring consistent adhesion along the entire mandrel surface despite the inherent gap-generating processes
Solution Approach 2:
The mandrel geometry is changed from a uniform cylindrical shape to a tapered shape with varying cross-sectional dimensions. This parameter change in the mandrel structure allows the oxide layer to maintain consistent adhesion by offsetting the gaps formed during deposition through the geometric taper
2Ease of manufacture
If the mandrel cross-sectional size is uniform, then the deposition process is simpler, but gaps are generated between the oxide layer and mandrel affecting pattern uniformity
Solution Approach 1:
The mandrel is designed with a tapered structure where the cross-sectional size gradually decreases from the top end to the bottom end. This creates local geometric variation that compensates for the uniform gap formation during oxide layer deposition, ensuring consistent adhesion along the entire mandrel surface despite the inherent gap-generating processes
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 method ensures precise and uniform high-density pattern formation by offsetting gaps caused by gas or material differences, maintaining the outer contour of the isolation layer and enhancing adhesion, resulting in improved pattern transfer accuracy and density.
Implementation Method 1
etching the sacrificial layer to enable the sacrificial layer to form a mandrel corresponding to the photoresist one by one
Implementation Method 2
an oxide layer 200 is covered and deposited on the mandrel by an atomic deposition process
Data Source
AI summary
Provided is a method of high-density pattern forming, which includes: providing a substrate; forming a hard mask layer on the substrate; forming a sacrificial layer on the hard mask layer; forming photoresists arranged at intervals on the sacrificial layer; etching the sacrificial layer to enable the sacrificial layer to form a mandrel corresponding to the photoresist one by one, wherein a cross-sectional size of the mandrel gradually decreases from an end of the mandrel away from the hard mask layer to an end close to the hard mask layer; forming an isolation layer on the mandrel; removing the isolation layer on the top of the mandrel, the isolation layer covering the hard mask layer, and the mandrel to form an isolation sidewall pattern; and transferring the isolation sidewall pattern to the hard mask layer.