Reticle Matching Patterns for Semiconductor Array Stitching

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Solution Overview

Problem

Existing methods for joining reticles to create large semiconductor layout patterns are limited by the size of matching patterns, which are often too large to fit within the normal array granularity, leading to inefficient use of reticles and increased costs due to the need for non-uniform partial reticles and frequent reticle changes.

Innovation Solution

The method involves distinguishing between bulk and peripheral sub-reticles, with peripheral sub-reticles including matching patterns that can be positioned externally to the bulk sub-reticles and the circuit, allowing for improved optical adjustment and matching, including the use of 'wild logic' and displacing matching patterns to enhance reticle alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If matching patterns are positioned within the normal array granularity, then reticle size is reduced, but array size is limited to 2x2 patterns

Engineering Contradiction:

Improvereticle sizeVSAvoidarray size

Core Design Contradiction:

Area of stationary objectVSAdaptability or versatility

Solution Approach 1:

The patent positions matching patterns outside the normal array granularity boundaries, effectively moving them to a different spatial dimension relative to the circuit patterns. This allows the matching patterns to be located in peripheral regions of the reticle that do not consume valuable array area, thereby enabling larger array configurations beyond the conventional 2x2 limit while maintaining adequate reticle size for manufacturing.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If non-uniform partial reticles are used to create larger patterns, then array size is increased, but manufacturing cost increases

Engineering Contradiction:

Improvearray sizeVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent divides the reticle into distinct functional regions: bulk sub-reticles containing circuit patterns and peripheral sub-reticles containing matching patterns. This segmentation allows uniform reticle designs to be used across multiple arrays, reducing manufacturing complexity and cost. The peripheral sub-reticles can be systematically designed and reused, eliminating the need for custom non-uniform reticles for each array configuration.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The peripheral sub-reticles containing matching patterns are designed to be universal components that can be applied across different array configurations and sizes. This multi-functional design allows the same reticle structure to support various array dimensions (1xn, 2x2, and larger), reducing the need for multiple specialized reticle designs and thereby lowering manufacturing costs.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If reticles are changed frequently to create larger arrays, then array size is increased, but processing time increases

Engineering Contradiction:

Improvearray sizeVSAvoidprocessing time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent pre-positions matching patterns in peripheral sub-reticles during the reticle design phase, preparing the infrastructure for large array fabrication in advance. This preliminary arrangement of matching patterns allows for seamless reticle stitching and alignment when creating extended arrays, eliminating the need for frequent reticle changes and associated processing time losses during production.

Inventive Principle:

Principle #10Preliminary action

4Area of stationary object

If matching patterns are positioned at the edge of reticles, then reticle utilization is optimized, but optical adjustment becomes difficult

Engineering Contradiction:

Improvereticle utilizationVSAvoidoptical adjustment

Core Design Contradiction:

Area of stationary objectVSEase of operation

Solution Approach 1:

The patent introduces peripheral sub-reticles as intermediary elements between the bulk sub-reticles containing circuits and the matching patterns. These peripheral sub-reticles provide dedicated space for matching patterns to be positioned optimally for optical alignment, serving as a buffer zone that facilitates easier optical adjustment and stitching while maintaining high reticle utilization through systematic design of the peripheral regions.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS7790336B2Method of joining a plurality of reticles for use in producing a semiconductor layout pattern, a computerized system for implementing such a method and a semiconductor mask arrangement produced by implementing such a method

Publication Date: 2010.09.07 TELEDYNE DIGITAL IMAGING INC(CA)

AI summary

A method for joining a plurality of reticles is used for producing a semiconductor layout pattern, so that the reticles will collectively map a circuit arrangement on a semiconductor substrate. A plurality of matching patterns is provided that are each geometrically linked to a respective particular reticle and through detecting pairwise correspondence among the matching patterns likewise correspondence among the associated reticles is ascertained.In particular, the method has bulk sub-reticles and peripheral sub-reticles, and a first matching pattern associates to a peripheral sub-reticle that abuts a bulk sub-reticle and a second matching pattern to the bulk sub-reticle at such distance therefrom that fitting of the peripheral sub-reticle between the second matching pattern and the bulk sub-reticle allows matching of the first and second matching patterns. The bulk sub-reticles are used to constitute an array of sub-reticles.