Composite Sintered Body for Plasma-Resistant Electrostatic Chucks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electrostatic chuck devices in semiconductor manufacturing are prone to plasma erosion, leading to reduced lifespan, and require high dielectric constant materials to maintain wafer temperature uniformity and withstand increased gas pressure, while existing ceramics-based solutions suffer from high dielectric loss tangents when exposed to low-frequency bias voltages.
Innovation Solution
A composite sintered body comprising metal oxide, silicon carbide, and silicate, with specific microstructural features such as dispersed silicon carbide crystals and controlled aggregation diameters, is used to form the base of the electrostatic chuck, offering high dielectric constants and low dielectric loss tangents across a wide temperature range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a ceramics sintered body is used as the base material in an electrostatic chuck device, then the dielectric constant can be maintained high for electrostatic attraction, but the material suffers from high dielectric loss tangent when exposed to low-frequency bias voltages
Solution Approach 1:
The patent employs a composite sintered body comprising aluminum oxide (90-99 wt%), silicon carbide (0.1-10 wt%), and silicon oxide (0.1-10 wt%). This composite structure combines the high dielectric constant of aluminum oxide with the low dielectric loss properties of silicon carbide and silicon oxide, achieving both high electrostatic attraction force and low dielectric loss tangent simultaneously
2Adaptability or versatility
If the base material is exposed to plasma during semiconductor manufacturing, then the electrostatic chuck device can perform plasma processes, but the base material suffers from plasma erosion that shortens its lifespan
Solution Approach 1:
The composite sintered body combines aluminum oxide with silicon carbide and silicon oxide, where silicon carbide provides enhanced plasma resistance. This composite structure maintains plasma process capability while significantly improving resistance to plasma erosion, thereby extending the base lifespan
Solution Approach 2:
The patent specifies that silicon carbide particles with an average particle size of 0.1-10 μm are uniformly dispersed throughout the aluminum oxide matrix. This local distribution of plasma-resistant silicon carbide particles provides targeted protection against plasma erosion while maintaining the overall dielectric properties of the base material
3Temperature
If gas pressure of the refrigerant is increased to improve cooling efficiency and temperature uniformity, then wafer temperature distribution improves, but the required electrostatic attraction force must be increased to prevent wafer detachment
Solution Approach 1:
The composite sintered body achieves a superior combination of high dielectric constant and low dielectric loss tangent, enabling high electrostatic attraction force generation. This allows the system to withstand increased refrigerant gas pressure for improved cooling efficiency while maintaining sufficient attraction force to prevent wafer detachment
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 composite sintered body is less susceptible to plasma erosion, maintains high dielectric performance, and extends the lifespan of electrostatic chuck devices while ensuring effective wafer temperature control and ion scattering suppression during microfabrication.
Implementation Method 1
The composite sintered body is less susceptible to plasma erosion
Implementation Method 2
an electrostatic attraction electrode that generates an electrostatic force (Coulomb's force) between itself and the wafer placed on the placing surface
Implementation Method 3
a technique for cooling the wafer placed on a sample stage by providing fine grooves in the sample stage and making a gaseous refrigerant (for example, helium) flow in the grooves
Data Source
AI summary
A composite sintered body including: a metal oxide as a main phase; silicon carbide as a sub-phase; and silicate of a metal element that is included in the metal oxide, in which the average aggregation diameter of the silicate in the field of view of 600 μm2 at a magnification of 1000 times is 5 μm or lower.