Vacuum-Chamber Charge Grid for Wafer Static Control
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Solution Overview
Problem
Conventional methods struggle to accurately and rapidly inject or remove static electricity from semiconductor substrates, particularly in high-density environments, leading to defects and pattern deformation due to arcing and uneven charge distribution.
Innovation Solution
A static electricity control device using a charged particle generation unit, grid, and substrate support within a vacuum chamber, which generates charged particles through VUV rays and process gas reactions, and controls voltage application to inject or remove static electricity by adjusting the grid and substrate support separation distance and voltage levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional ionizer methods are used to remove static electricity from substrates, then static electricity removal is achieved, but the process is slow and ineffective for high-density charge environments
Solution Approach 1:
The patent changes the fundamental parameters of the ionizer system by adjusting gas flow rates, radio frequency power levels, and electrode configurations to generate higher density plasma and charged particles. This enables faster neutralization of static electricity while maintaining effectiveness in high-density charge environments that conventional methods cannot handle.
Solution Approach 2:
The system dynamically adjusts operating parameters such as gas flow rates and power levels during the static electricity removal process. The ionizer can modulate its output to match the charge density on the substrate, enabling adaptive control that optimizes both speed and effectiveness for varying charge conditions.
2Reliability
If high voltage is applied to the central part of the substrate for static electricity removal, then charge neutralization is achieved, but arcing and pattern deformation occur
Solution Approach 1:
The patent applies different voltage levels and charged particle densities to different regions of the substrate. The ionizer system creates a non-uniform charged particle distribution that matches the spatial variation of static electricity on the substrate, applying higher neutralization intensity to highly charged areas and lower intensity to lightly charged areas, preventing arcing while ensuring complete neutralization.
Solution Approach 2:
The system replaces direct high-voltage electrical contact methods with a plasma-based charged particle approach. Instead of applying high voltage directly to the substrate surface, the system uses ionized gas to deliver charge neutralization, which eliminates arcing and electrical breakdown while maintaining effective charge removal.
3Power
If the grid and substrate support are placed far apart, then charged particle generation is efficient, but charged particle density at the substrate decreases
Solution Approach 1:
The system uses pulsed or periodic operation modes where gas flow and power application are cyclical. This periodic action creates bursts of high-density charged particles that travel efficiently from the ionizer to the substrate, maintaining both generation efficiency and particle density at the target surface.
Solution Approach 2:
The patent employs multiple ionizer electrodes or zones that replicate the charged particle generation process across different spatial locations. This creates multiple sources of charged particles that collectively deliver sufficient density to the substrate while maintaining efficient generation at each source, effectively overcoming the distance attenuation problem.
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
Enables precise and rapid static electricity management on semiconductor substrates, minimizing defects and enhancing the reliability of semiconductor manufacturing processes.
Implementation Method 1
generates charged particles including positive ions and electrons by generating a vacuum ultraviolet (VUV) ray and reacting the VUV ray with a process gas inside the vacuum chamber
Data Source
AI summary
Embodiments of the present invention relate to a technology for easily adjusting a level of static electricity required for a substrate according to a semiconductor process by injecting static electricity into the substrate or removing static electricity already formed on the substrate. A static electricity control device for injecting static electricity into a substrate disposed in a vacuum chamber or removing static electricity formed on the substrate in a semiconductor processing system, according to an embodiment, comprises: a charged particle generation unit, disposed on an upper side inside the vacuum chamber, that generates charged particles including positive ions and electrons by generating a vacuum ultraviolet ray (VUV) and reacting the VUV with a process gas inside the vacuum chamber; a grid provided with a plurality of holes, disposed on a lower side of the charged particle generation unit, that selectively pass the type of charged particles downward according to an input voltage; a substrate support, disposed below the grid and having the substrate positioned thereon, that is made of a conductive material and guides the charged particles passing through the grid toward the substrate at a predetermined density according to an input bias voltage; and a static electricity control unit that controls the static electricity of the substrate by supplying a pulsed voltage to at least one of the grid and the substrate support, wherein the grid and the substrate support are arranged so as to have a separation distance that is within four times the mean free path of the process gas according to environmental conditions of the vacuum chamber.