Photosensitive Polyimide Resin for Void-Resistant Copper Interfaces
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Solution Overview
Problem
Conventional polyimide resins used in semiconductor devices experience void formation at the interface with copper layers during high-temperature storage tests, leading to reduced adhesion and potential short-circuiting or disconnection.
Innovation Solution
A photosensitive resin composition combining a photosensitive polyimide precursor with a specific compound, represented by formula (B1), is used to minimize void formation at the interface between copper and polyimide layers, enhancing adhesion and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polyimide resin is used for insulating material, then heat resistance and mechanical properties are excellent, but void formation occurs at the interface with copper layers during high-temperature storage tests, leading to reduced adhesion
Solution Approach 1:
The patent introduces a specific compound (component B with formula B1 containing sulfur or oxygen atom) as an intermediary substance between the polyimide precursor and copper layer. This compound acts as a mediator that prevents direct harmful interaction between copper and polyimide during high-temperature storage, thereby preventing void formation while maintaining excellent adhesion.
Solution Approach 2:
The patent modifies the chemical composition parameters of the photosensitive resin by incorporating component B with specific molecular structure (formula B1) at controlled concentrations (0.1-10 parts by mass per 100 parts of component A). This parameter change in the resin composition prevents the harmful void formation mechanism while preserving the desired adhesion properties.
2Productivity
If photosensitive polyimide precursor composition is used, then processing time is greatly reduced, but void formation still occurs during high-temperature storage tests
Solution Approach 1:
The patent adds component B as an intermediary protective agent that specifically addresses the adhesion stability issue during high-temperature storage. This mediator prevents the chemical or physical degradation at the copper-polyimide interface that would otherwise occur during storage, ensuring reliability without sacrificing the processing speed benefits of photosensitive materials.
Solution Approach 2:
The patent creates a composite photosensitive resin composition by combining polyimide precursor (component A) with the protective compound (component B) in specific ratios. This composite material integrates the fast-processing characteristics of photosensitive polyimide with the protective adhesion-stabilizing properties of component B, achieving both productivity and reliability.
3Reliability
If high-temperature storage test is performed, then reliability of the device is evaluated, but Cu component moves to polyimide layer causing void formation and potential short-circuiting
Solution Approach 1:
Component B acts as a protective intermediary layer or barrier that prevents copper atoms from migrating into the polyimide matrix during high-temperature storage. This mediator blocks the diffusion path of copper, eliminating the harmful effect of Cu migration while allowing the reliability evaluation test to proceed.
Solution Approach 2:
The patent utilizes the high-temperature storage test conditions that would normally cause copper migration and void formation as an opportunity to demonstrate and validate the protective effect of component B. The harmful thermal energy and copper diffusion tendency are converted into a beneficial validation process that confirms the adhesion stability and reliability of the device.
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 composition effectively reduces void formation and ensures high adhesion between copper and polyimide layers after high-temperature storage tests, preventing short-circuiting or disconnection in semiconductor devices.
Implementation Method 1
a component (A) as a photosensitive polyimide precursor
Implementation Method 2
a component (B) having a structure represented by the following formula (B1)
Data Source
AI summary
A semiconductor device having a copper wiring and an insulating layer provided on the copper wiring, where after storage in air with a humidity of 5% for 168 hours at 150° C., the area of void portion of the copper wiring is 10% or less at the copper wiring surface in contact with the insulating layer. The insulating layer contains at least one polyimide that has (i) a structure derived from 4,4′-oxydiphthalic acid dianhydride and a structure derived from 4,4′-diaminodiphenyl ether; or (ii) a structure derived from 3,3′4,4′-biphenyltetracarboxylic acid dianhydride and a structure derived from 4,4′-diaminodiphenyl ether; or (iii) a structure derived from 4,4′-oxydiphthalic acid dianhydride and a structure derived from 2,2′-dimethyl-4,4′-diaminobiphenyl.