Metal Feature Fill Using De-Inhibition CVD for Void-Free Deposition
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Solution Overview
Problem
The challenge in semiconductor fabrication is filling features with thin metal films without voids, especially as devices shrink and patterning becomes more complex, leading to issues with metal film stacks and inhibition of metal nucleation.
Innovation Solution
The method involves performing a de-inhibition operation to reduce or remove inhibition effects, which includes exposing the feature to hydrogen gas or a plasma generated from hydrogen gas, and optionally using argon gas to control the de-inhibition process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If inhibition treatment is applied to prevent metal nucleation on feature surfaces, then metal deposition is controlled in features, but metal deposition is also inhibited on field regions causing non-uniform deposition
Solution Approach 1:
The patent divides the substrate into two distinct zones: features (where metal deposition is desired) and field regions (where metal deposition is to be prevented). By applying inhibition treatment selectively to feature surfaces through targeted exposure to inhibition gas or plasma, the patent achieves spatial segmentation of deposition control. This allows uniform metal films to be deposited in features while preventing nucleation on field regions, resolving the contradiction between achieving uniform deposition and maintaining deposition control.
2Reliability
If metal deposition is performed in inhibited features, then void-free filling is achieved, but deposition rate and coverage are reduced
Solution Approach 1:
The patent applies inhibition treatment to feature surfaces before metal deposition to prevent nucleation and ensure void-free filling. By performing this preliminary inhibition step, the patent creates controlled surfaces that guide metal deposition uniformly throughout the feature volume. The inhibition acts as a template that ensures complete coverage without voids, accepting a trade-off in deposition rate for improved reliability of the fill process.
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
This approach allows for effective filling of features with metal, including tungsten, molybdenum, ruthenium, and cobalt, by decoupling inhibition from deposition, ensuring uniform deposition across the substrate, and preventing voids and line bending in features.
Implementation Method 1
the de-inhibition treatment includes exposing the feature to H2 gas or a plasma generated from H2 gas... the de-inhibition treatment desorbs nitrogen from feature surfaces and/or field regions
Implementation Method 2
exposing the feature to hydrogen (H2) gas, or a plasma generated from H2 gas
Implementation Method 3
performing a first chemical vapor deposition (CVD) operation including exposing the feature to a metal precursor and hydrogen (H2)... performing a second CVD operation to deposit metal in the feature
Data Source
AI summary
Provided herein are methods of filling features with metal including inhibition of metal nucleation. One aspect of the disclosure relates to a method including providing a substrate having a feature and field regions, wherein the feature is to be filled with metal, the feature including feature surfaces and a feature opening; performing an inhibition treatment to inhibit metal deposition on at least some of the feature surfaces; after performing the inhibition treatment, performing a first chemical vapor deposition (CVD) operation including exposing the feature to a metal precursor and hydrogen (H2); after performing the first CVD operation, performing a de-inhibition treatment to decrease inhibition; and after decreasing inhibition, performing a second CVD operation to deposit metal in the feature and/or on the field regions.