Semiconductor Patterning with Segmented Mandrels for Mixed-Length Features

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Solution Overview

Problem

Current Self Aligned Doubled Patterning (SADP) and Reverse Self Aligned Doubled Patterning (SARP) technologies face challenges in fabricating patterns of different lengths, limiting their ability to meet requirements for fine structures and increasing process complexity and cost.

Innovation Solution

A patterning method involving the formation of mandrel structures with sub-portions of different lengths, followed by the creation of trenches and mask patterns of varying lengths, allows for the etching of patterns with distinct dimensions, improving process applicability and reducing complexity and cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If SADP or SARP technology is used to fabricate dense array patterns, then pattern density is improved, but the ability to fabricate patterns of different lengths is lost

Engineering Contradiction:

Improvepattern densityVSAvoidcapability to fabricate patterns of different lengths

Core Design Contradiction:

Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The mandrel structure is divided into a first sub-portion and a second sub-portion along its extending direction. The first sub-portion has a first length and the second sub-portion has a second length, enabling different trench lengths to be formed between adjacent sidewalls. This segmentation allows the process to produce both short and long patterns simultaneously while maintaining high density.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If conventional patterning methods are used to fabricate fine structures of different lengths, then adaptability is improved, but process complexity and cost increase

Engineering Contradiction:

Improvecapability to fabricate fine structures of different lengthsVSAvoidprocess complexity and cost

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The mandrel structure serves multiple functions: it defines both short trenches (between adjacent sidewalls) and long trenches (between non-adjacent sidewalls). By forming sidewalls on both sides of the mandrel and selectively removing portions, a single mandrel structure enables the fabrication of patterns with different lengths using the same basic process flow, reducing complexity and cost.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS20250006494A1Patterning methods, semiconductor structures and memory

Publication Date: 2025.01.02 YANGTZE MEMORY TECH CO LTD

AI summary

The present application discloses a patterning method, a semiconductor structure and a memory. The patterning method includes: after forming a mandrel structure in a mask layer on a side of a to-be-etched layer, removing part of the mandrel structure to form a first trench with a smaller length and a second trench with a larger length, and forming a first mask pattern and a second mask pattern through the first trench and the second trench so as to form a first patterned structure and a second patterned structure of different lengths. The present application can improve the applicability of the patterning method, and reduce the process difficulty and cost of fine patterning for forming patterns of different sizes, such that the patterning method provided by the present application can meet more process requirements.