Ceramic Substrate with Tungsten Electrode for Stable Insulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ceramics substrates used in electrostatic chucks for semiconductor manufacturing often have insulation resistance that decreases with increasing temperature due to the presence of sintering agents, which can compromise bonding strength with conductive materials like tungsten.
Innovation Solution
A ceramics substrate with an aluminum oxide body and a sintered tungsten-based electric conductor pattern containing nickel oxide and silicon dioxide, eliminating the need for sintering agents to improve sinterability and adhesiveness while maintaining high purity and low temperature dependency of insulation resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If sintering agents (e.g., silica, magnesia, calcia, yttria) are contained in alumina ceramics to improve sinterability, then bonding strength between ceramics and tungsten conductor is achieved, but insulation resistance decreases as temperature increases
Solution Approach 1:
The invention extracts and removes sintering agents from the alumina ceramics composition to eliminate the source of temperature-dependent insulation resistance degradation. By using sintering agent-free alumina ceramics, the patent achieves stable insulation resistance across temperature ranges while maintaining bonding strength through alternative means (tungsten paste formulation and firing process optimization).
Solution Approach 2:
The invention changes the chemical composition parameters of the ceramics by eliminating sintering agents and instead optimizing the tungsten paste composition with specific additives. This parameter change allows the system to achieve bonding without compromising insulation resistance stability at elevated temperatures.
2Reliability
If sintering agent-free alumina ceramics are used to maintain low temperature dependency of insulation resistance, then bonding strength between ceramics and tungsten cannot be obtained
Solution Approach 1:
The invention introduces organic additives (cellulose, starch, or dextrin) as intermediaries in the tungsten paste formulation. These organic materials facilitate bonding between the tungsten and sintering agent-free alumina ceramics during the firing process, enabling adhesion without requiring sintering agents in the ceramics themselves, thus preserving insulation resistance stability.
Solution Approach 2:
The invention creates a composite system where sintering agent-free alumina ceramics are combined with specially formulated tungsten paste containing organic additives. This composite approach allows the ceramics to maintain their insulating properties while the composite paste structure provides the necessary bonding mechanism during sintering.
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 enhances sinterability and adhesiveness between the ceramics and tungsten, maintaining the substrate's characteristics without sintering agents, and reduces temperature-dependent insulation resistance degradation.
Implementation Method 1
the green sheet and the electrically conductive paste are sintered simultaneously
Implementation Method 2
it may be impossible to obtain bonding strength between the ceramics and the tungsten which serves as a conductor
Data Source
AI summary
A ceramics substrate includes: a substrate body; and an electric conductor patient that is provided in the substrate body. The substrate body is made of ceramics containing aluminum oxide. The electric conductor pattern is a sintered body that contains tungsten as a main component and further contains nickel oxide, aluminum oxide and silicon dioxide.