DRAM Bit Line Select Layout for Contact Resistance Matching

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Solution Overview

Problem

Existing semiconductor structures face challenges in maintaining consistent electrical properties and switching characteristics of bit line select line transistors due to mismatches, which affect data read and write operations in dynamic random access memory (DRAM) devices.

Innovation Solution

The semiconductor structure is designed with active areas arranged in an array, featuring a bit line select structure with interconnected gates and contact structures positioned close to a connecting line to ensure consistent electrical properties and improved switching characteristics by reducing resistance and enhancing the on-state current of transistors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If contact structures are positioned away from the connecting line, then manufacturing is easier, but electrical consistency and switching characteristics of bit line select line transistors deteriorate due to resistance mismatches

Engineering Contradiction:

Improveelectrical consistency of bit line select line transistorsVSAvoidcontact structure positioning

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies local quality by positioning contact structures at specific locations close to the connecting line rather than uniformly distributing them. This localized positioning optimizes the electrical properties of bit line select line transistors by reducing resistance mismatches, while the manufacturing process remains feasible through standard photolithography and etching techniques that can accommodate this specific contact arrangement.

Inventive Principle:

Principle #3Local quality

2Reliability

If gate structures are extended and interconnected, then switching characteristics improve, but device complexity increases

Engineering Contradiction:

Improveswitching characteristics of bit line select line transistorsVSAvoidgate structure configuration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple gate structures into an interconnected gate configuration where gates are extended and connected to form a unified bit line select line transistor structure. This merging improves switching characteristics by ensuring consistent electrical properties across the transistor, while the interconnected design allows for simplified control signaling despite the increased structural integration.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS12548618B2Semiconductor structure and manufacturing method therefor, and memory

Publication Date: 2026.02.10 CHANGXIN MEMORY TECH INC

AI summary

A semiconductor structure includes: multiple active areas arranged in an array along intersecting first and second directions and spaced apart by an isolation structure; a bit line select structure comprising a first gate, a second gate, a third gate and a fourth gate located on four mutually adjacent active areas, and at least one connecting line located on the isolation structure; and multiple contact structures, each of the multiple contact structures being located on one side, close to the connecting line, of both sides of a respective gate and connected with a respective one of the multiple active areas, and an orthographic projection of the contact structure on a plane where the active area is located being at a position, close to the connecting line, in the active area.