Inverted HEMT Structure With Dielectric Region for Lower Substrate Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High substrate power loss in high-electron-mobility transistors (HEMTs) due to low silicon resistance and high substrate capacitance, limiting power added efficiency (PAE) in silicon-based semiconductor devices.
Innovation Solution
Incorporating a dielectric region, such as a cavity, between the semiconductor substrate and the interconnect structure to increase substrate resistance and reduce substrate capacitance, achieved by using a semiconductor device with a vertically inverted configuration and a high-resistance semiconductor substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a silicon-based semiconductor substrate is used for HEMT fabrication, then the device can be manufactured with standard silicon processes, but substrate power loss increases due to low substrate resistance and high substrate capacitance
Solution Approach 1:
A dielectric layer is introduced as an intermediary between the silicon substrate and the HEMT device. This dielectric layer acts as a mediator that increases the effective substrate resistance and reduces substrate capacitance, thereby reducing substrate power loss while maintaining compatibility with silicon-based manufacturing processes
Solution Approach 2:
The substrate resistance and capacitance parameters are modified by introducing a dielectric layer with specific electrical properties. The dielectric layer changes the effective electrical parameters of the substrate interface, increasing resistance and decreasing capacitance to reduce power loss
2Loss of energy
If the substrate resistance is increased to reduce power loss, then substrate power loss decreases, but the substrate capacitance also changes which may affect device performance
Solution Approach 1:
The dielectric layer parameters (thickness, permittivity) are specifically selected and optimized to achieve the desired balance between increasing substrate resistance (to reduce power loss) and maintaining appropriate substrate capacitance levels (to preserve device performance). This controlled parameter change resolves the contradiction
3Loss of energy
If a dielectric region is introduced to increase substrate resistance, then substrate power loss is reduced, but the device structure becomes more complex
Solution Approach 1:
The dielectric layer serves as a simple intermediary element that can be integrated into existing HEMT fabrication processes without requiring fundamental structural changes. This minimalistic approach reduces power loss while adding only a single layer, thereby limiting the increase in device complexity
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
Significantly reduces substrate power loss and increases PAE, enhancing performance for applications like 5G mobile communications by decreasing substrate capacitance and increasing interface resistance.
Implementation Method 1
Incorporating a dielectric region, such as a cavity, between the semiconductor substrate and the interconnect structure to increase substrate resistance and reduce substrate capacitance
Data Source
AI summary
Various embodiments of the present disclosure are directed towards an integrated circuit (IC) chip comprising a semiconductor device that is inverted and that overlies a dielectric region inset into a top of a semiconductor substrate. An interconnect structure overlies the semiconductor substrate and the dielectric region and further comprises an intermetal dielectric (IMD) layer. The IMD layer is bonded to the top of the semiconductor substrate and accommodates a pad. A semiconductor layer overlies the interconnect structure, and the semiconductor device is in the semiconductor layer, between the semiconductor layer and the interconnect structure. The semiconductor device comprises a first source/drain electrode overlying the dielectric region and further overlying and electrically coupled to the pad. The dielectric region reduces substrate capacitance to decrease substrate power loss and may, for example, be a cavity or a dielectric layer. A contact extends through the semiconductor layer to the pad.