Batch Ozone Cure Chamber for Dielectric Film Stability
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Solution Overview
Problem
The decreasing feature sizes in semiconductor devices require low resistivity conductive materials and low dielectric constant insulation materials, particularly for PMD and IMD layers, which are often unstable when initially deposited and need curing or annealing processes to enhance stability.
Innovation Solution
A chamber design that allows for simultaneous batch processing of wafers with a vertically aligned housing having separate processing areas for high-temperature ozone curing and N2O steam annealing, equipped with a multi-zone heater, gas distribution, and wafer transport system to manage ozone and steam introduction and exhaust, enabling efficient curing and annealing of multiple wafers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If carbon-based dielectric layers are used to achieve low dielectric constant (k<3.0), then RC time delay is reduced and cross-talk is prevented, but the films are unstable when initially deposited and require additional curing processes
Solution Approach 1:
The chamber is divided into two separate processing areas: a first batch processing area for loading/unloading wafers and a second batch processing area for ozone curing. This segmentation allows simultaneous independent processing operations, enabling curing to occur while wafers are being loaded or unloaded in the other area, thereby resolving the contradiction between film stability requirements and processing throughput.
Solution Approach 2:
The dual batch processing areas enable continuous operation where one area is actively curing wafers while the other is being loaded or unloaded. This eliminates idle time between processing steps and maintains continuous productive action, addressing the productivity loss associated with sequential curing operations.
2Reliability
If high temperature ozone curing is performed to stabilize dielectric films, then film stability is improved, but processing time and energy consumption increase
Solution Approach 1:
By separating the curing function into a dedicated second batch processing area with its own wafer transport and processing zone, the system can cure multiple wafers simultaneously in batch mode rather than processing them individually or sequentially through a single chamber, thereby reducing total curing time while maintaining film stability.
Solution Approach 2:
The ozone curing process is performed in a controlled oxygen-rich environment within the sealed second processing area, allowing high-temperature curing to proceed efficiently and uniformly across all wafers in the batch. The inert atmosphere control enables complete curing in a single continuous operation rather than requiring multiple lower-temperature steps, reducing total process time.
3Productivity
If multiple wafers are processed sequentially in a single chamber, then equipment complexity is minimized, but productivity and throughput are reduced
Solution Approach 1:
The processing chamber is segmented into two vertically stacked batch processing areas, each with its own wafer transport system. This allows independent simultaneous operation of loading/unloading in the first area and curing in the second area, effectively doubling throughput capability while maintaining a relatively compact vertical footprint that limits complexity growth.
Solution Approach 2:
Instead of expanding the chamber horizontally to accommodate multiple processing zones, the design stacks processing areas vertically in two dimensions. This vertical arrangement increases throughput capacity without proportionally increasing overall equipment footprint or operational complexity, as wafers are transferred between levels through a shared transport mechanism.
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 solution enables effective curing and annealing of wafers in a controlled environment, improving the stability of dielectric layers and reducing RC time delay and cross-talk between metalization levels, while optimizing device power consumption.
Implementation Method 1
a multi-zone heater operatively coupled to the housing to heat the first and second processing areas independent of each other
Implementation Method 2
various carbon-based dielectric layers that are now commonly used in the semiconductor industry have dielectric constants below 3.0. Many of these carbon-based layers are relatively unstable when initially deposited and are subsequently cured in an oxygen environment
Implementation Method 3
cured in an oxygen environment and/or annealed to increase the films stability
Implementation Method 4
a N2O steam anneal process in the first batch processing area
Data Source
AI summary
A substrate processing chamber for processing a plurality of wafers in batch mode. In one embodiment the chamber includes a vertically aligned housing having first and second processing areas separated by an internal divider, the first processing area positioned directly over the second processing area; a multi-zone heater operatively coupled to the housing to heat the first and second processing areas independent of each other; a wafer transport adapted to hold a plurality of wafers within the processing chamber and move vertically between the first and second processing areas; a gas distribution system adapted to introduce ozone into the second area and steam into the first processing area; and a gas exhaust system configured to exhaust gases introduced into the first and second processing areas.