Semiconductor Field Plate Segmentation for High-Voltage Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor devices with field plates on silicon nitride films between gate and drain electrodes experience breakdowns under high-temperature, high-voltage operations due to poor film quality and thin film thickness at step portions, leading to reduced service life and reliability.
Innovation Solution
A semiconductor device design featuring a first field plate separated from the step portion and electrically connected to the source electrode, with a shield electrode extending over the field plate and gate electrode to reduce electric field intensity and prevent breakdowns, using a layered structure of silicon nitride films and metal electrodes to enhance withstand voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a field plate is formed on a silicon nitride film along the step portion of the gate electrode, then the field intensity can be reduced and withstand voltage can be improved, but the film quality deteriorates and breakdown occurs under high-temperature, high-voltage operation
Solution Approach 1:
The field plate structure is divided into two separate components: a first field plate formed on the silicon nitride film between the gate and drain electrodes, and a second field plate formed on an insulating film between the gate and source electrodes. This segmentation eliminates the problematic step portion formation while maintaining field intensity control and withstand voltage improvement, thereby preventing breakdown under high-temperature, high-voltage operation.
2Strength
If the field plate is formed to follow the step portion shape of the gate electrode, then the field intensity distribution can be optimized, but the film thickness becomes thin and poor quality leading to breakdown
Solution Approach 1:
The field plate is segmented into two separate structures: the first field plate positioned between gate and drain, and the second field plate positioned between gate and source. This eliminates the need for a continuous field plate following the gate electrode step portion, thereby avoiding thin film formation while still achieving optimized field intensity distribution and high withstand voltage through the combined effect of both segmented field plates.
3Reliability
If a continuous field plate structure is used to reduce feedback capacitance, then the gate-drain capacitance can be minimized, but the film quality at step portions deteriorates causing breakdown
Solution Approach 1:
The field plate structure is segmented into two separate field plates formed at different locations and times in the manufacturing process. This segmentation eliminates the step portion formation that causes film quality deterioration, while the combined effect of both field plates maintains low feedback capacitance between gate and drain, ensuring operational stability without compromising film quality.
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 prevents breakdowns and extends the service life of semiconductor devices under high-temperature, high-voltage conditions by reducing electric field intensity and ensuring higher withstand voltages between electrodes.
Implementation Method 1
the field intensity can be reduced in the vicinity of a region that is located between the gate electrode and the drain electrode and is also located below the field plate
Implementation Method 2
a first insulating film formed on the semiconductor layer and covering the gate electrode
Data Source
AI summary
A semiconductor device includes a source electrode and a drain electrode formed on an active region of the semiconductor layer, a gate electrode formed on the active region of the semiconductor layer, a first insulating film formed on the semiconductor layer and covering the gate electrode, the first insulating film having a step portion following a shape of the gate electrode, a first field plate formed on the insulating film and located between the gate electrode and the drain electrode and separated from the step portion, a second insulating film formed on the first insulating film to cover the step portion and the first field plate, and a shield electrode formed on the second insulating film, the shield electrode extending from a portion located above the first field plate and a portion located above the gate electrode.