Variable Capacitance Chuck Structure for Uniform Plasma Density
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Solution Overview
Problem
The uneven plasma density distribution within a substrate processing chamber due to the etching of the focus ring, which affects the substrate processing results, is not adequately addressed by existing technologies.
Innovation Solution
A substrate processing apparatus with a variable capacitance device that includes adjustable electrodes in an insulating layer, controlled by a distance control unit, to maintain uniform plasma density by adjusting capacitance based on sensed electrical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a focus ring is provided inside the chamber to uniformize the density of plasma, then plasma density uniformity is improved, but the focus ring is etched during the etching process causing deformation and affecting substrate processing results
Solution Approach 1:
The patent introduces a variable capacitance device as an intermediary component between the focus ring and the substrate processing system. This device mediates the plasma distribution by adjusting capacitance values to compensate for the focus ring's geometric changes during etching, thereby maintaining plasma density uniformity without requiring the focus ring to remain physically stable
Solution Approach 2:
The patent dynamically changes the capacitance parameter of the variable capacitance device during the substrate processing process. By adjusting the capacitance value in response to detected focus ring deformation or plasma density variations, the system compensates for geometric changes in the focus ring and maintains optimal plasma distribution
2Productivity
If the focus ring is etched over the course of the etching process, then the etching process continues, but the height and shape of the focus ring are deformed affecting equipment performance and substrate processing results
Solution Approach 1:
The patent implements a feedback mechanism where the system detects changes in the focus ring's geometry or plasma density distribution during the etching process and responds by adjusting the capacitance of the variable capacitance device. This closed-loop control allows the system to maintain substrate processing precision even as the focus ring is continuously etched
Solution Approach 2:
The patent transforms the static focus ring system into a dynamic one by introducing a variable capacitance device that can adjust its electrical properties in real-time. This dynamic adjustment compensates for the continuous geometric changes in the focus ring during etching, maintaining processing quality throughout the entire process
3Manufacturing precision
If a variable capacitance device with adjustable electrodes is introduced to maintain uniform plasma density, then plasma density uniformity is improved, but device complexity increases
Solution Approach 1:
The variable capacitance device is designed to perform multiple functions: it serves as both a plasma distribution control mechanism and a compensation mechanism for focus ring deformation. By integrating these functions into a single device, the patent reduces the need for additional separate components that would further increase system 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 maintains uniform plasma density, reduces the need for focus ring replacement, and improves semiconductor yield by stabilizing power lines and reducing loss rates.
Implementation Method 1
two electrodes formed in the insulating layer, wherein a distance between the two electrodes is adjustable to form a variable capacitance
Implementation Method 2
an electromagnetic field is formed in a chamber. The electromagnetic field excites a processing gas provided in the chamber, into a plasma state
Implementation Method 3
Plasma refers to a state of ionized gas composed of ions, electrons, radicals, and the like and is generated by very high temperature, strong electric fields, or radio frequency (RF) electromagnetic fields
Implementation Method 4
a sensor unit provided in the chamber and sensing an electrical property of a first periphery, which is around a ceramic puck, and an electrical property of a second periphery, which is around the focus ring
Data Source
AI summary
A substrate processing apparatus is provided. The substrate processing apparatus includes: a chuck member; a ceramic puck disposed on the chuck member; a focus ring disposed to surround the ceramic puck; an insulating layer disposed below the focus ring to surround the chuck member; and two electrodes formed in the insulating layer, wherein a distance between the two electrodes is adjustable to form a variable capacitance.