*2.1. Modelling of UWBG (Ga2O3) Semiconductors*

In this article, the design of UWBG semiconductors is described briefly since the modeling and fabrication of the UWBG semiconductor is not the main objective of this study. The UWBG switches are modeled considering the drain current and source implementation [25], while the channel is isolated using the doping structure as shown in Figure 1. The Ga2O<sup>3</sup> parameters that are used in this study to build the proposed inverter are demonstrated in Table 1. These parameters are only used in technology computeraided design (TCAD) to evaluate the conduction behavior of the Ga2O<sup>3</sup> devices. The I-V characteristics of these switches are shown in Figure 2.

Firstly, a Ga2O<sup>3</sup> n-type epitaxial layer having 100 nm thickness is developed over a β-Ga2O<sup>3</sup> (single crystal), which is semi-insulating in nature. Secondly, A dopant with a concentration of 2 <sup>×</sup> <sup>10</sup><sup>17</sup> cm−<sup>3</sup> is applied to dope the epitaxial layer. Tin (Si/Sn) implantation is used to form the 50 nm deep drain regions and the dopant concentration. Finally, a metal gate of 2 µm length and a work function of 5.93 eV is implanted on the top of a dielectric film gate with 20 nm length. The drain and gate are separated by a 4 µm gap [26].

To evaluate the performance of the Ga2O<sup>3</sup> devices, accurate switching behavior is very crucial. However, since the switching behavior of the UWBG devices cannot be evaluated using TCAD, SPICE models of the Ga2O<sup>3</sup> are required for further analysis [27]. In this regard, the level 1 Schichman–Hodges model parameters as shown in Table 2 are extracted

from TCAD and were used to develop the SPICE model. The model parameters along with the switching, conduction, drain-source voltage, and drain current are implemented in LTSpice software to build a simulation model of the Ga2O<sup>3</sup> switching device. The parameters that are used to build the LTSpice simulation model are shown in Table 2. *Micromachines* **2021**, *12*, x FOR PEER REVIEW 4 of 20

**Figure 1.** Modelling UWBG semiconductor switches. **Figure 1.** Modelling UWBG semiconductor switches. *CB* **= 2 × 1017 cm-3 Source**

**Table 1.** Parameters used in TCAD for analyzing conduction behavior of Ga2O<sup>3</sup> switches. *LT* **= 100 nm** *CB* **= 9 × 1019 cm-3** *CB* **= 9 × 1019 cm-3**


**Drain**

gate of 2 μm length and a work function of 5.93 eV is implanted on the top of a dielectric

**Parameters Values**  Bandgap energy 4.8 eV

Firstly, a Ga2O3 n-type epitaxial layer having 100 nm thickness is developed over a β-Ga2O3 (single crystal), which is semi-insulating in nature. Secondly, A dopant with a concentration of 2 × 1017 cm−3 is applied to dope the epitaxial layer. Tin (Si/Sn) implantation is used to form the 50 nm deep drain regions and the dopant concentration. Finally, a metal gate of 2 μm length and a work function of 5.93 eV is implanted on the top of a dielectric

> Electron affinity 4 eV Electron mobility 118 cm2/Vs

To evaluate the performance of the Ga2O3 devices, accurate switching behavior is very crucial. However, since the switching behavior of the UWBG devices cannot be evaluated using TCAD, SPICE models of the Ga2O3 are required for further analysis [27]. In

**Parameters Values**  Bandgap energy 4.8 eV Effective density of states at 300 K 4.45 × 1018 cm−<sup>3</sup> Electron affinity 4 eV Electron mobility 118 cm2/Vs

**Table 1.** Parameters used in TCAD for analyzing conduction behavior of Ga2O3 switches.

To evaluate the performance of the Ga2O3 devices, accurate switching behavior is very crucial. However, since the switching behavior of the UWBG devices cannot be evaluated using TCAD, SPICE models of the Ga2O3 are required for further analysis [27]. In

**Table 1.** Parameters used in TCAD for analyzing conduction behavior of Ga2O3 switches.

film gate with 20 nm length. The drain and gate are separated by a 4 μm gap [26]. **Figure 2.** I-V characteristics of Ga2O3 semiconductor switches. **Figure 2.** I-V characteristics of Ga2O<sup>3</sup> semiconductor switches.


**Table 2.** Parameters used in SPICE for analyzing switching behavior of Ga2O<sup>3</sup> switches.
