High-k Field Relief Dielectric Structure for Breakdown and On-Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fabricating semiconductor devices with increasingly higher performance while meeting reliability specifications is challenging, particularly in achieving reliable operation with smaller feature sizes.
Innovation Solution
A microelectronic device with a high-k field relief dielectric structure is introduced, which includes materials such as silicon nitride, silicon oxynitride, Al2O3, BaTiO3, and HfO2, raising the dielectric constant above that of silicon dioxide. This structure is integrated into a trench formed by Local Oxidation of Silicon (LOCOS) and is positioned to abut the gate dielectric layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silicon dioxide field relief dielectric structure is used, then manufacturing simplicity is maintained, but channel hot carrier performance deteriorates, breakdown resistance decreases, and specific on resistance increases
Solution Approach 1:
The patent changes the dielectric constant parameter of the field relief dielectric from 3.9 (silicon dioxide) to higher values (silicon nitride k=7.9, silicon oxynitride k=4-7, or other high-k materials). This parameter change improves channel hot carrier performance, breakdown resistance, and specific on resistance while maintaining the basic LOCOS trench structure, thus resolving the contradiction between reliability improvement and device complexity.
2Reliability
If silicon dioxide field relief dielectric structure is used, then manufacturing process simplicity is maintained, but breakdown resistance deteriorates
Solution Approach 1:
The patent increases the dielectric constant parameter from 3.9 to higher values by substituting silicon dioxide with silicon nitride, silicon oxynitride, or other high-k materials. This parameter change enhances breakdown resistance while the manufacturing process remains similar to conventional LOCOS techniques, resolving the contradiction between improved reliability and manufacturing simplicity.
3Reliability
If silicon dioxide field relief dielectric structure is used, then manufacturing simplicity is maintained, but specific on resistance increases
Solution Approach 1:
The patent changes the dielectric constant parameter from 3.9 (silicon dioxide) to higher values (silicon nitride k=7.9, silicon oxynitride k=4-7, or other high-k materials with k>3.9). This parameter reduction in specific on resistance is achieved through the increased dielectric constant, which enhances electric field management, while maintaining compatibility with existing LOCOS manufacturing processes.
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 high-k field relief dielectric structure improves channel hot carrier performance, increases breakdown resistance, and reduces the specific on-resistance of the microelectronic device compared to devices with a silicon dioxide field relief dielectric structure.
Implementation Method 1
The high-k field relief dielectric structure raises the dielectric constant of the field relief dielectric above that of pure silicon dioxide which has a dielectric constant of 3.9
Implementation Method 2
a trench formed by Local Oxidation of Silicon (LOCOS) and removal of the locos layer leaving a dielectric trench with local oxidation of silicon profile
Data Source
AI summary
Semiconductor devices including a high-k field relief dielectric structure are described. The microelectronic device comprises a substrate including a body region and a drain drift region on the substrate, a gate dielectric layer extending over the body region and the drift region, a drain drift trench is formed by removal of silicon dioxide from a LOCOS silicon region, a high-k field relief dielectric structure laterally abutting the gate dielectric layer at a location in the drift region, and a gate electrode on the gate dielectric layer and the field relief dielectric layer. Increasing the dielectric constant of the field relief dielectric structure may improve channel hot carrier performance, improve breakdown voltage, and reduce the specific on resistance. A drain drift trench formed in a trench left after removal of silicon dioxide in a LOCOS region provides improved trench depth uniformity.