Semiconductor Trench Key Patterning With Spacer-Assisted Mask Transfer
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Solution Overview
Problem
The challenge of manufacturing semiconductor devices with finer patterns is exacerbated by decreasing process margins, making it difficult to achieve reliable manufacturing processes.
Innovation Solution
A method involving the formation of a stacked structure on a substrate, followed by the creation of photoresist patterns and mask layers to define trenches and trench keys, using spacer insulating layers and multiple mask layers to ensure precise pattern transfer and formation of trench keys without damaging underlying mask layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If down-scaling of semiconductor devices is pursued to achieve finer patterns, then manufacturing precision is improved, but process margins decrease making manufacturing increasingly difficult
Solution Approach 1:
The manufacturing process is divided into multiple sequential steps with separate mask layers (first mask layer, second mask layer) and photoresist patterns (first photoresist pattern, second photoresist pattern). Each layer and pattern serves a specific function in defining different features, allowing complex fine patterns to be manufactured through staged processing rather than a single step, thereby maintaining reliability while achieving precision.
Solution Approach 2:
The first mask layer and first photoresist pattern are formed in advance to define initial features and protect underlying structures. The spacer insulating layer is formed beforehand to provide a protective barrier. These preliminary actions prepare the structure for subsequent processing steps, ensuring that critical features are established before finer details are added, thus maintaining manufacturing reliability during down-scaling.
2Manufacturing precision
If multiple mask layers and photoresist patterns are used to achieve precise trench key formation, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The complex task of forming trench keys with high precision is segmented into multiple independent steps: forming the first photoresist pattern with line-and-space features, forming a surrounding second photoresist pattern, creating spacer insulating layers, forming separate first and second mask layers, and performing selective removal steps. Each segment handles a specific aspect of the pattern formation, making the overall complex process more controllable and manufacturable.
Solution Approach 2:
The spacer insulating layer acts as an intermediary element between the photoresist patterns and the final trench key structure. It provides a protective barrier that prevents damage to underlying mask layers during etching operations, while also serving as a template for defining the trench key geometry. This intermediary layer simplifies the overall process by decoupling the pattern definition from the etching step.
3Reliability
If spacer insulating layers and multiple mask layers are used to protect underlying structures, then reliability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The first mask layer and spacer insulating layer are formed in advance to establish protective barriers and alignment references before subsequent etching steps. The first photoresist pattern is formed with specific line-and-space dimensions that are transferred to the first mask layer, creating a precise template that guides later processing. These preliminary actions ensure that critical alignment relationships are established before finer features are added, reducing the precision burden on later steps.
Solution Approach 2:
The pattern from the first photoresist pattern is copied onto the first mask layer through photolithographic exposure and development. This copied pattern serves as a faithful replica that preserves the dimensional accuracy and alignment information from the photoresist to the mask layer, ensuring that precision is maintained through the pattern transfer process while the mask layer provides protection during subsequent etching operations.
Data Source
AI summary
A method of manufacturing a semiconductor device may forming a first photoresist pattern on a stacked structure, the first photoresist pattern including a second portion surrounding first portions having a line-and-space shape, transferring a pattern of the first photoresist pattern to a first mask layer, forming a spacer insulating layer covering sidewalls of remaining portions of the first mask layer, forming a second mask layer filling spaces between portions of the spacer insulating layer, removing the spacer insulating layer, forming first insulating patterns having a line and space shape and a second insulating pattern surrounding the first insulating patterns using the first mask layer and the second mask layer as masks, forming a trench by removing the first insulating patterns using a second photoresist pattern as a mask, and forming a trench key by transferring a pattern of the trench to a lower region of the stacked structure.