Electrostatic Chuck Insulating Substrate Residual Adsorption
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Solution Overview
Problem
In semiconductor applications, electrostatic chucks face a challenge with residual adsorption that worsens over time due to continuous plasma exposure, leading to increased deformation and damage of work pieces during detachment.
Innovation Solution
An electrostatic chuck with an insulating substrate containing Mn and a transition element like Fe or Cr, where the ratio of the transition element to Mn is 1 or more, effectively suppresses residual adsorption by facilitating reversible charge exchange, preventing the deterioration of adsorption suppression power over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If plasma exposure is continuously performed to remove fixed electric charges, then residual adsorption is reduced initially, but the power of suppressing residual adsorption deteriorates over time
Solution Approach 1:
The invention changes the chemical composition parameters of the insulating substrate by adding specific elements (Fe, Cr, Ni, Cu, Co, or Zn) at controlled concentrations (0.01-10 wt%). This compositional parameter change enables the material to maintain stable electrical properties and suppress residual adsorption throughout its service life without deterioration from continuous plasma exposure.
Solution Approach 2:
The invention creates a composite insulating substrate by combining traditional ceramic materials (alumina, aluminum nitride, silicon nitride, or silicon oxide) with trace amounts of transition metals (Fe, Cr, Ni, Cu, Co, or Zn). This composite structure leverages the electrical properties of the added elements to stabilize charge distribution and prevent residual adsorption deterioration over time.
2Force
If DC voltage is applied to the adsorption electrode to immobilize the work piece, then adsorption force is generated, but fixed electric charges accumulate on the insulating substrate
Solution Approach 1:
The added elements (Fe, Cr, Ni, Cu, Co, or Zn) act as intermediary charge traps within the insulating substrate. They provide alternative pathways for charge dissipation and prevent the accumulation of fixed electric charges that would otherwise lead to residual adsorption, while still allowing the DC voltage to generate the necessary adsorption force.
Solution Approach 2:
By modifying the electrical parameters of the insulating substrate through element addition, the invention changes the charge trapping and dissipation characteristics. This enables the substrate to maintain low residual adsorption even during repeated cycles of DC voltage application and plasma exposure.
3Ease of operation
If a lifting pin is used to detach the work piece from the adsorption face, then the work piece can be removed, but the work piece may be deformed or damaged when residual adsorptive force is large
Solution Approach 1:
The modified insulating substrate with added elements (Fe, Cr, Ni, Cu, Co, or Zn) provides self-service by automatically maintaining low residual adsorption levels. This eliminates the need for aggressive plasma exposure or complex control mechanisms, allowing work pieces to be detached easily and safely without deformation or damage throughout the device's service life.
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 configuration allows for easy detachment of work pieces without deformation or damage, maintaining effective adsorption suppression even after prolonged plasma exposure, thereby reducing production time and costs.
Implementation Method 1
an electrostatic chuck utilizing an electrostatic adsorptive force is used... an electrostatic adsorptive force is generated such as a Coulomb's force due to dielectric polarization or a Johnsen-Rahbek force due to a slight leakage current
Implementation Method 2
an electrostatic adsorptive force is generated such as a Coulomb's force due to dielectric polarization
Implementation Method 3
a region which includes at least an upper face of the insulating substrate being made of ceramics containing Mn and a first transition element composed of at least one of Fe and Cr... a ratio C2/C1 of a content C2 (mol) of the first transition element to a content C1 (mol) of Mn contained in the insulating substrate being 1 or more
Data Source
AI summary
There is provided an electrostatic chuck an electrostatic chuck in which it is hard for the power of suppressing residual adsorption to deteriorate over time. There is provided an electrostatic chuck including an insulating substrate, and an adsorption electrode, wherein a region which includes at least an upper face of the insulating substrate containing Mn is made of ceramics containing a first transition element composed of at least one of Fe and Cr, and a ratio C2/C1 of a content C2 (mol) of the first transition element to a content C1 (mol) of Mn contained in the insulating substrate is 1 or more.