Semiconductor Device Blocking Layers for Outgassing Control
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Solution Overview
Problem
In semiconductor devices, the outgassing of materials from low-k dielectric layers during high-temperature processes can lead to failures due to the lack of effective blocking mechanisms, resulting in poor device characteristics and reliability.
Innovation Solution
The implementation of a semiconductor device structure that includes a first intermetal dielectric (IMD) layer with a low-k material, a first blocking layer with a higher dielectric constant oxide, and a second blocking layer with a nitride material, which reduces outgassing and enhances bonding between layers, thereby improving device characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a low-k dielectric layer is used to reduce parasitic capacitance, then parasitic capacitance is reduced, but material outgassing occurs during high-temperature processes
Solution Approach 1:
A blocking layer comprising silicon nitride and silicon oxide is introduced as an intermediary between the low-k dielectric layer and the upper structures. This blocking layer acts as a mediator that prevents harmful gas molecules generated from the low-k dielectric layer during high-temperature processes from migrating upward, while simultaneously serving as an etch stop layer to prevent over-etching of the low-k dielectric layer.
2Object-generated harmful factors
If a blocking layer is added to prevent outgassing, then outgassing is reduced, but device structure complexity increases
Solution Approach 1:
The blocking layer is designed to perform multiple functions simultaneously: (1) serving as a diffusion barrier to prevent outgassing of materials from the low-k dielectric layer, (2) acting as an etch stop layer to prevent over-etching during via hole formation, and (3) providing a stable interface for subsequent processing steps. This multi-functionality reduces the need for additional separate layers, thereby minimizing the increase in structural complexity.
3Manufacturing precision
If high-temperature processes are used for manufacturing, then manufacturing precision is improved, but material outgassing from low-k dielectric layer increases
Solution Approach 1:
The blocking layer is formed prior to high-temperature processing steps such as copper plug formation and via hole etching. This preliminary action ensures that when high-temperature processes are subsequently applied to achieve manufacturing precision, the blocking layer is already in place to prevent material outgassing from the low-k dielectric layer, thereby allowing high-temperature processing to proceed without generating harmful outgassing effects.
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 use of blocking layers effectively decreases material outgassing, enhances bonding, and reduces parasitic capacitance, leading to improved semiconductor device reliability and performance.
Implementation Method 1
Some materials included in the low-k dielectric layer may be outgassed during a high-temperature process
Implementation Method 2
enhances bonding between layers
Data Source
AI summary
A semiconductor may include a first inter metal dielectric (IMD) layer, a first blocking layer on the first IMD layer, a metal wiring and a second blocking layer. The first inter metal dielectric (IMD) layer may be formed on a substrate, the first IMD layer may include a low-k material having a dielectric constant lower than a dielectric constant of silicon oxide. The first blocking layer may be formed on the first IMD layer. The first blocking layer may include an oxide having a dielectric constant higher than the dielectric constant of the first IMD layer. The metal wiring may be through the first IMD layer and the first blocking layer. The second blocking layer may be formed on the metal wiring and the first blocking layer. The second blocking layer may include a nitride. The first and second blocking layers may reduce or prevent from the out gassing, so that a semiconductor device may have good characteristics.