Multi-zone PECVD Electrostatic Chuck for Uniform Film Deposition
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Solution Overview
Problem
Plasma-enhanced chemical vapor deposition (PECVD) processes face non-uniformity in film deposition due to gas flow patterns, plasma non-uniformity, temperature variations, and substrate warpage, leading to process variations in subsequent lithographic and etch processes.
Innovation Solution
A multi-zone PECVD apparatus with an electrostatic chuck featuring temperature control zones and spot lamp zones, along with conductive plates and plate bias circuits, is used to maintain uniform temperature and electrostatic chucking force across the substrate, ensuring consistent film deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If PECVD process is used for film deposition, then deposition can proceed at relatively low temperature, but non-uniformity in film thickness occurs due to temperature variations across substrate
Solution Approach 1:
The electrostatic chuck is divided into multiple independently controlled temperature zones (e.g., first temperature zone, second temperature zone, third temperature zone) with different temperature control circuits. This allows each zone to be controlled separately to compensate for temperature variations across the substrate, thereby maintaining uniform film deposition while operating at low temperatures.
Solution Approach 2:
Different regions of the electrostatic chuck are assigned different temperature characteristics through localized heating elements and independent temperature control circuits. This enables each local area to have optimized temperature conditions suitable for uniform deposition, addressing the non-uniformity problem while maintaining overall low-temperature operation.
2Temperature
If PECVD process is used for film deposition, then deposition can proceed at relatively low temperature, but non-uniformity in film thickness occurs due to plasma non-uniformity
Solution Approach 1:
The electrostatic chuck is segmented into multiple zones with independent temperature control, allowing localized adjustment of temperature conditions in different plasma regions. This compensates for plasma non-uniformity effects and ensures consistent film thickness across the substrate while maintaining low-temperature deposition.
3Temperature
If PECVD process is used for film deposition, then deposition can proceed at relatively low temperature, but non-uniformity in film thickness occurs due to gas flow patterns
Solution Approach 1:
The electrostatic chuck is divided into multiple temperature control zones that can be independently adjusted. This allows compensation for gas flow pattern variations by optimizing temperature conditions in each zone, achieving uniform film deposition at low temperature despite non-uniform gas distribution.
4Ease of operation
If electrostatic chuck is used to hold substrate, then substrate positioning is achieved, but non-uniform electrostatic chucking force causes substrate warpage
Solution Approach 1:
The electrostatic chuck incorporates multiple independently controllable conductive plates or electrode segments. This allows the electrostatic field to be divided into multiple zones with independently adjustable voltage, enabling uniform distribution of chucking force across the substrate surface and preventing warpage while maintaining secure positioning.
Solution Approach 2:
Different regions of the electrostatic chuck are equipped with independently controllable electrodes that can apply localized electrostatic forces. This enables each area to exert appropriate chucking force according to local substrate conditions, ensuring uniform force distribution and preventing substrate warpage while maintaining secure positioning.
5Manufacturing precision
If multi-zone temperature control and plate bias circuits are added, then uniformity of temperature and chucking force is improved, but device complexity increases
Solution Approach 1:
The electrostatic chuck is designed to serve multiple functions simultaneously: it provides substrate positioning, applies electrostatic chucking force, and controls temperature distribution. By integrating temperature control circuits and conductive plates into the chuck structure itself, the apparatus achieves uniform film deposition without requiring separate external systems for each function, thereby managing complexity.
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 solution achieves uniform film deposition across the substrate, reducing process variations and improving the consistency of subsequent lithographic and etch processes by independently controlling temperature and electrostatic chucking force.
Implementation Method 1
depositing a film on the substrate by generating a radio frequency plasma of the precursor gas employing the radio frequency power source
Implementation Method 2
a plurality of plate bias circuits configured to independently electrically bias a respective one of the plurality of conductive plates with a different direct current bias voltage to obtain a more uniform electrostatic chucking force across the electrostatic chuck
Implementation Method 3
a plurality of spot lamp zones located below the respective temperature control zones, each of the spot lamp zones including at least one spot lamp located between a bottom portion of the vacuum enclosure and a backside surface of the electrostatic chuck
Data Source
AI summary
An apparatus includes an electrostatic chuck and located within a vacuum enclosure. A plurality of conductive plates can be embedded in the electrostatic chuck, and a plurality of plate bias circuits can be configured to independently electrically bias a respective one of the plurality of conductive plates. Alternatively or additionally, a plurality of spot lamp zones including a respective set of spot lamps can be provided between a bottom portion of the vacuum enclosure and a backside surface of the electrostatic chuck. The plurality of conductive plates and/or the plurality of spot lamp zones can be employed to locally modify chucking force and to provide local temperature control.