Photoresist Etch-Back for Stable Pattern Distribution

Solution Overview

Problem

Existing semiconductor fabrication methods face challenges in achieving stable and reliable photoresist pattern distribution, particularly in preventing pattern collapse during the photolithography process, especially as feature sizes are reduced.

Innovation Solution

The method involves forming a photoresist layer with an initial thickness, exposing and then partially removing it to create a reduced thickness, which helps in forming a stable photoresist pattern that prevents collapse and improves resolution by controlling the aspect ratio through an etch back process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a thicker photoresist layer is used, then the distribution of the photoresist pattern is improved, but the photoresist pattern is more likely to collapse

Engineering Contradiction:

Improvedistribution of photoresist patternVSAvoidstability of photoresist pattern

Core Design Contradiction:

Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The photoresist layer is segmented into two distinct thickness regions: a first thickness region (thicker) that improves pattern distribution and resolution, and a second thickness region (thinner) that prevents pattern collapse. This segmentation is achieved through selective removal of photoresist material in specific areas, allowing each region to fulfill its specific function optimally.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the photoresist layer are given different local qualities in terms of thickness. The first thickness region is maintained or enhanced for areas requiring improved distribution and resolution, while the second thickness region is created in areas where collapse prevention is critical. This local differentiation allows the photoresist layer to simultaneously achieve both improved distribution and enhanced stability.

Inventive Principle:

Principle #3Local quality

2Stability of the object's composition

If a thinner photoresist layer is used, then the photoresist pattern is prevented from collapsing, but the distribution of the photoresist pattern deteriorates

Engineering Contradiction:

Improvestability of photoresist patternVSAvoiddistribution of photoresist pattern

Core Design Contradiction:

Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The photoresist layer is segmented into two distinct thickness regions: a first thickness region (thicker) that improves pattern distribution and resolution, and a second thickness region (thinner) that prevents pattern collapse. This segmentation is achieved through selective removal of photoresist material in specific areas, allowing each region to fulfill its specific function optimally.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the photoresist layer are given different local qualities in terms of thickness. The first thickness region is maintained or enhanced for areas requiring improved distribution and resolution, while the second thickness region is created in areas where collapse prevention is critical. This local differentiation allows the photoresist layer to simultaneously achieve both improved distribution and enhanced stability.

Inventive Principle:

Principle #3Local quality

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 enhances the distribution and stability of the photoresist pattern, preventing collapse and improving the resolution and precision of the photolithography process, even at smaller feature sizes.

Implementation Method 1

exposing a portion of the photoresist layer to form an exposed portion and a non-exposed portion of the photoresist layer

Methodology Applied

Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP4307344A1Methods of fabricating semiconductor device

Publication Date: 2024.01.17 SAMSUNG ELECTRONICS CO LTD

Figure 1
Figure 2A~2B
Figure 2C~2D

AI summary

A method of fabricating a semiconductor device is provided, which includes forming (S11) a photoresist layer on a lower structure to have a first thickness, exposing (S12) a portion of the photoresist layer to form an exposed portion and a non-exposed portion of the photoresist layer, removing (S13) a part of the photoresist layer to form a photoresist layer having a second thickness that smaller than the first thickness, and removing (S14) the exposed portion or the non-exposed portion of the photoresist layer having the second thickness to form a photoresist pattern.