TCAD Application Hetero Structure Devices Example 

DC and RF Characterization of HEMTs 

The purpose of this Sentaurus TCAD simulation project is to provide a template setup for the DC and RF characterization of high electron mobility transistors (HEMTs).

For HEMTs, the following simulations are performed: IdVgs, a family of IdVds curves, on-state and off-state breakdown, and RF analysis. The template is based on an InGaAs HEMT; however, the project structure and input files can be used for any HEMT with only minor modifications.

For each of the simulated IV curves, relevant electrical parameters such as pinch-off voltage, transconductance, drain saturation current, and breakdown voltage are calculated. Furthermore, RF parameters such as ft and fmax, as well as other twoport network and RF gain parameters, are computed.

Figure 1

HEMT device generated by Sentaurus Structure Editor. For better viewing, different scales are used for the x-axis and y-axis.

Figure 2

On-state and off-state breakdown calculated using the direct method: blue curve is IdVds at Vgs = 0 V (on-state breakdown) and red curve is IdVds at Vgs=-1.5 V (off-state breakdown).

Figure 3

Off-state breakdown calculated using the drain-current injection method: drain voltage as function of gate voltage for a constant drain current level of Id = 500 (blue), 300 (green), and 200 (red) mA/mm

Figure 4

RF parameter h21 as function of frequency for a gate bias of Vgs = 0 V: absolute value |h21| (red), real part (blue), imaginary part (green), and phase (black dashes)

Figure 5

The RF parameters s11 and s22 are shown on a Smith chart for a gate bias of 0 V and frequencies between 100 MHz and 1 THz. Shown is a screen capture of the Inspect window. By clicking a frequency label in the legend, the corresponding data point in the Smith chart is highlighted.

The simulation project is part of the Sentaurus TCAD distribution at:


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