Analytical and Physical Investigation on Source Resistance in InGaAs Quantum-Well High-Electron-Mobility Transistors

Area of Science:

• Semiconductor Device Physics
• Materials Science

Background:

• Source resistance (R) significantly impacts High-Electron Mobility Transistor (HEMT) performance.
• Accurate modeling of R is essential for optimizing device design and predicting performance.

Purpose of the Study:

• To develop a fully analytical model for source resistance (R) in InGaAs quantum-well HEMTs.
• To investigate the physical factors contributing to R, particularly barrier tunneling resistivity.

Main Methods:

• Derived a new R model by solving coupled quadratic differential equations with boundary conditions.
• Utilized six physical and geometrical parameters for model derivation.
• Fabricated cap-TLM and recessed-TLM structures to extract model parameters.

Main Results:

• The developed R model showed excellent agreement with measured R values from fabricated TLM devices and previous HEMT devices.
• Identified barrier tunneling resistivity as a critical factor in reducing R in state-of-the-art HEMTs.

Conclusions:

• The analytical model provides an accurate method for predicting source resistance in InGaAs HEMTs.
• Significant improvements in HEMT performance necessitate a substantial reduction in barrier tunneling resistivity.
• Optimizing ohmic contact characteristics and gate-to-source spacing offers marginal benefits without addressing barrier tunneling resistivity.