Composite Contact Via Structure for 3D Memory Alignment

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Solution Overview

Problem

Conventional 3D memory devices face challenges in maintaining structural integrity and alignment due to high tensile stress and strength properties of conductive materials in contact vias, leading to distortion and misalignment issues.

Innovation Solution

Incorporating a stress compensation material with high compressive stress and strength in the central portion of contact vias, surrounded by conductive material, to balance and offset the tensile stress properties, thereby reducing distortion and improving structural alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conductive material with high tensile stress and strength is used in contact vias, then the structural strength and reliability are improved, but distortion and misalignment occur due to stress accumulation

Engineering Contradiction:

Improvestructural strengthVSAvoidalignment precision

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The patent introduces a stress compensation material with compressive stress properties to counterbalance the tensile stress generated by the conductive material. This counterweight approach neutralizes the net stress in the contact via, preventing distortion and misalignment while maintaining structural strength.

Inventive Principle:

Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The contact via structure is designed as a composite system comprising both conductive material and stress compensation material. This composite structure combines the beneficial tensile strength of the conductive material with the compressive stress properties of the compensation material, achieving both strength and dimensional stability.

Inventive Principle:

Principle #40Composite materials

2Reliability

If the amount of conductive material deposited in contact vias is increased, then the electrical conductivity is improved, but the bowing and distortion increase proportionally

Engineering Contradiction:

Improveelectrical conductivityVSAvoidcontact via straightness

Core Design Contradiction:

ReliabilityVSShape

Solution Approach 1:

The stress compensation material acts as a counterweight to the tensile stress induced by increased conductive material deposition. By providing compressive stress, it offsets the bowing effect that would otherwise increase proportionally with the amount of conductive material, allowing higher conductivity without proportional distortion.

Inventive Principle:

Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The patent changes the stress parameter of the contact via system by introducing material with opposite stress characteristics. This parameter change (from net tensile to balanced or net compressive stress) enables increased conductive material deposition without the proportional increase in bowing that would occur in conventional single-material structures.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If conventional single-material contact via structure is used, then the manufacturing process is simple, but stress mismatch and distortion occur between array and staircase regions

Engineering Contradiction:

Improveprocess simplicityVSAvoidstress uniformity

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The contact via is designed as a composite structure with conductive material and stress compensation material. This composite approach addresses stress mismatch between array and staircase regions by providing internal stress balance, preventing distortion while maintaining manufacturability through established deposition techniques.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The stress compensation material is selectively placed within the contact via structure where stress accumulation occurs. This local quality approach targets the specific problem area (contact via stress) without requiring changes to the entire manufacturing process, maintaining ease of manufacture while improving stress uniformity.

Inventive Principle:

Principle #3Local quality

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 stress compensation material effectively minimizes bowing and misalignment, enhancing the structural properties and reliability of 3D memory devices by balancing the tensile stress of conductive materials within contact vias.

Implementation Method 1

Methodology Applied

Scientific EffectStress compensation:

Data Source

PatentUS12002759B2Apparatuses including a conductive contact including a dielectric material surrounded by a conductive material

Publication Date: 2024.06.04 LODESTAR LICENSING GROUP LLC

AI summary

An apparatus comprising at least one contact structure. The at least one contact structure comprises a contact, an insulating material overlying the contact, and at least one contact via in the insulating material. The at least one contact structure also comprises a dielectric liner material adjacent the insulating material within the contact via, a conductive material adjacent the dielectric liner material, and a stress compensation material adjacent the conductive material and in a central portion of the at least one contact via. The stress compensation material is at least partially surrounded by the conductive material. Memory devices, electronic systems, and methods of forming the apparatus are also disclosed.