Spiral Oscillating Resistive Field Plate for Low Leak Current
Solution Overview
Problem
High voltage ICs using resistive field plates experience high leak currents, leading to increased power consumption when on standby, due to the trade-offs between resistive field plate design and manufacturing complexity, accuracy, and cost.
Innovation Solution
A semiconductor device with a thin film resistance layer that spirally oscillates in the thickness direction of the substrate, forming a resistive field plate on an insulating film with undulations, to increase the total resistance value and reduce leak current without increasing the sheet resistance or the area of the breakdown voltage region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a resistive field plate is provided to enhance potential enforceability on the depletion layer, then reliability is improved, but leak current increases leading to higher power consumption
Solution Approach 1:
The field plate is extended into the thickness direction of the insulating film, transforming from a planar structure to a three-dimensional structure. This vertical extension increases the total resistance value by adding more resistive material in series, thereby reducing leak current and power consumption while maintaining the potential enforceability function on the depletion layer.
Solution Approach 2:
The field plate is configured with a curved or undulated shape rather than a straight line. This curved configuration increases the path length of the resistive material between the electrodes, effectively increasing the total resistance value and reducing leak current while maintaining the same planar footprint area.
2Loss of energy
If the total resistance value of the resistive field plate is increased to reduce leak current, then power consumption is reduced, but the area of the breakdown voltage region must be increased
Solution Approach 1:
Instead of increasing the planar area to add more resistive material, the invention extends the field plate into the thickness direction of the insulating film. This vertical dimension provides additional resistance without increasing the chip area, allowing leak current reduction while maintaining a compact breakdown voltage region footprint.
Solution Approach 2:
The field plate structure is optimized locally by varying its thickness or material properties at different positions along its length. This allows for increased resistance in specific regions without uniformly increasing the entire structure's area, enabling targeted resistance enhancement while maintaining area efficiency.
3Loss of energy
If the sheet resistance of the resistive thin film is increased to reduce leak current, then power consumption is reduced, but manufacturing precision and cost are adversely affected
Solution Approach 1:
Instead of increasing sheet resistance which requires precise control of thin film properties, the invention increases total resistance by extending the field plate into the thickness direction. This approach uses standard sheet resistance values with conventional manufacturing tolerances, avoiding the need for high-precision thin film deposition while still achieving the desired resistance value reduction for lower power consumption.
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 design effectively reduces power consumption during standby by minimizing leak current while maintaining manufacturing accuracy and cost-effectiveness, improving the yield and reducing the complexity of the manufacturing process.
Implementation Method 1
a thin film resistance layer, one end side of which is connected to the first main electrode terminal and the other end side of which is connected to the second main electrode terminal, which circles spirally on the insulating film in such a way as to surround the first main electrode terminal, wherein the thin film resistance layer circles while oscillating in a thickness direction of the semiconductor substrate
Data Source
AI summary
A semiconductor device includes a first main electrode terminal and second main electrode terminal disposed on the principal surface of a semiconductor substrate so as to be spaced from one another, an insulating film formed on the principal surface of the semiconductor substrate, and a thin film resistance layer. One end side of the thin film resistance layer is connected to the first main electrode terminal and the other end side of the thin film resistance layer is connected to the second main electrode terminal, the thin film resistance layer being spirally formed on the insulating film in such a way as to surround the first main electrode terminal. The thin film resistance layer extends while oscillating in a thickness direction of the semiconductor substrate.