Semiconductor Device Stabilizing Diode Forward Voltage
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Solution Overview
Problem
In semiconductor devices with both diode and IGBT regions on the same substrate, the parasitic diode's on-state causes fluctuations in forward voltage due to varying hole injection from the IGBT body region into the drift region, influenced by the gate electrode's potential application.
Innovation Solution
The semiconductor device incorporates a diode region with a first pillar region and an IGBT region with a second pillar region, both forming Schottky junctions, where the second pillar region has a lower resistance than the first, reducing hole injection from the IGBT body region into the drift region, thereby stabilizing the forward voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the parasitic diode is turned on in the semiconductor device, then current conduction is enabled, but hole injection from the IGBT body region into the drift region causes fluctuation in forward voltage
Solution Approach 1:
The patent applies local quality by creating asymmetric doping concentrations in different regions of the semiconductor device. Specifically, the anode region has a higher doping concentration (1E16 to 1E18 atoms/cm³) compared to the body region (1E14 to 1E16 atoms/cm³), and the drift region has a low doping concentration (1E12 to 1E14 atoms/cm³). This localized variation in doping concentration optimizes hole injection characteristics to reduce forward voltage fluctuation.
Solution Approach 2:
The patent utilizes parameter changes by adjusting the doping concentration ratios between different regions. The key parameter is the doping concentration ratio between the anode region and body region, which is controlled to be 10-100 times. Additionally, the drift region's low doping concentration (1E12 to 1E14 atoms/cm³) is specifically optimized to control hole injection and stabilize forward voltage during diode operation.
2Ease of operation
If the on-potential is applied to the gate electrode, then IGBT operation is enabled, but the quantity of holes injected into the drift region decreases, causing forward voltage fluctuation
Solution Approach 1:
The patent applies local quality by creating distinct doping profiles in different regions to control hole injection characteristics. The body region (1E14 to 1E16 atoms/cm³) and anode region (1E16 to 1E18 atoms/cm³) have different doping concentrations, which ensures that hole injection is dominated by the anode region rather than the body region, reducing gate voltage dependence.
Solution Approach 2:
The patent utilizes parameter changes by optimizing the doping concentration ratio between the anode region and body region to be 10-100 times. This parameter control ensures that the anode region contributes significantly more holes to the drift region than the body region, making the forward voltage less sensitive to gate electrode potential changes.
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
This configuration effectively suppresses the fluctuation in forward voltage of the diode region by controlling hole injection, regardless of the gate electrode's potential application, enhancing the semiconductor device's operational stability.
Implementation Method 1
The first pillar region and the anode electrode make a Schottky junction. The second pillar region and the emitter electrode make a Schottky junction.
Implementation Method 2
A resistance value of the second pillar region between the emitter electrode and the second barrier region is lower than a resistance value of the first pillar region between the anode electrode and the first barrier region
Implementation Method 3
a parasitic diode composed of a body region of the IGBT region, a drift region, and a cathode region of the diode region may be turned on when the semiconductor device operates as a diode
Data Source
AI summary
A technology capable of suppressing a fluctuation in voltage in a diode region is provided. A resistance value between the emitter electrode and the lower body region is lower than a resistance value between the anode electrode and the lower anode region when the semiconductor device operates as a diode. A quantity of holes between the emitter electrode and the second barrier region is smaller than a quantity of holes between the anode electrode and the first barrier region.