Ferromagnetic Memory Cell Using Semiconductor Fin Enclosure

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Solution Overview

Problem

Conventional ferromagnetic memory cells face challenges in accurate alignment of photolithographically defined features due to small feature sizes, leading to scalability issues and data retention problems.

Innovation Solution

A ferromagnetic memory cell is formed using a semiconductor fin enclosure with a ferromagnetic material, where the top surface of the ferromagnetic material is below the top surface of the semiconductor fin enclosure, allowing for self-alignment of features without photolithography and enhancing current density, thus addressing scalability and data retention issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If photolithography is used to define features in conventional ferromagnetic memory cells, then manufacturing process is established, but alignment accuracy deteriorates due to small feature sizes

Engineering Contradiction:

Improvealignment accuracyVSAvoidfeature size

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The semiconductor fin structure serves as a self-aligning template that automatically defines the position and dimensions of the ferromagnetic material layer. The fin enclosure structure confines the ferromagnetic material through physical geometry rather than photolithographic patterning, eliminating alignment errors associated with small feature photolithography while maintaining manufacturing feasibility

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces the photolithographic mechanical patterning system with a semiconductor-based structural confinement system. Instead of using light-based patterning to define features, the invention uses the physically formed semiconductor fin enclosure to mechanically confine and define the ferromagnetic material layer, achieving superior alignment accuracy

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If photolithographically defined features are used, then conventional manufacturing is maintained, but data retention deteriorates

Engineering Contradiction:

Improvedata retentionVSAvoidmanufacturing process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The semiconductor fin structure automatically defines the ferromagnetic material boundaries and provides structural support, eliminating the need for complex photolithographic alignment processes. This self-aligning approach improves data retention by ensuring precise feature definition while simplifying the manufacturing process to sequential deposition and formation steps

Inventive Principle:

Principle #25Self-service

3Area of moving object

If feature size is reduced for high density, then memory density improves, but alignment precision deteriorates

Engineering Contradiction:

Improvememory cell areaVSAvoidalignment precision

Core Design Contradiction:

Area of moving objectVSManufacturing precision

Solution Approach 1:

The patent transitions from planar photolithographic patterning to three-dimensional semiconductor fin structure confinement. By utilizing the vertical dimension of the fin enclosure to define the ferromagnetic material layer, the invention achieves precise alignment in miniaturized memory cells without being constrained by photolithographic resolution limits in the lateral dimension

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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

The solution enables improved alignment and data retention by increasing current density through the semiconductor fin, reducing leakage and Vt mismatch, and avoiding scalability problems associated with conventional memory cells.

Implementation Method 1

a ferromagnetic material within the semiconductor fin enclosure

Methodology Applied

Scientific EffectFerromagnetism: Ferromagnetism

Data Source

PatentUS7491994B2Ferromagnetic memory cell and methods of making and using the same

Publication Date: 2009.02.17 INTERNATIONAL BUSINESS MACHINE CORPORATION

AI summary

In a first aspect, a first apparatus is provided. The first apparatus is a memory cell that includes (1) a semiconductor fin enclosure formed on an insulating layer of a substrate; and (2) a ferromagnetic material within the semiconductor fin enclosure. A top surface of the ferromagnetic material is below a top surface of the semiconductor fin enclosure. Numerous other aspects are provided.