Improvements From SiC Substrate Thinning in AlGaN/GaN HEMTs: Disparate Effects on Contacts, Access and Channel Regions

Parvez, Bazila; Jha, Jaya; Upadhyay, Prashant; Bhardwaj, Navneet; Yadav, Yogendra Kumar; Upadhyay, Bhanu B.; Ganguly, Swaroop

doi:10.1109/led.2021.3068863

Cited by 6 publications

(2 citation statements)

References 18 publications

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“…The device structure, as seen in figure 1, was inspired by [17][18][19] which served as an idea for the geometric dimensions and the epi-layer stack. It comprises of a 500 μm thick SiC substrate [20,21], an AlN nucleation layer (40 nm thick), a GaN buffer layer (590 nm thick), a local GaN channel layer quantum well (QW) (10 nm thick), and an undoped AlGaN barrier film with 30% aluminum content). We have five possible structures based on varied barrier thicknesses, namely Structures A, B, C, D and E designed with barrier thickness 16 nm, 19 nm, 22 nm, 25 nm, and 28 nm respectively, as illustrated in figure 1.…”

Section: Design Parametersmentioning

confidence: 99%

Exploring the impact of AlGaN barrier thickness and temperature on normally-on GaN HEMT performance

Hidayat,

Usman

2024

Eng. Res. Express

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Theoretical studies are conducted on varying barrier thicknesses in GaN/AlGaN HEMTs, as well as the effect of temperature fluctuation on device functionality. Structures A, B, C, D and E are designed each with barrier thickness 16 nm, 19 nm, 22 nm, 25 nm, and 28 nm respectively. A theoretical model is explained that helps to understand the impacts of barrier thickness variation on surface barrier height, strain relaxation and 2DEG concentration. The concept is further expanded to include the GaN HEMT's drain and transfer properties. Investigations are also done on how different thermal impacts affect the functionality of the device. We contemplate alloy disorder, interfaceroughness (IFR) as well as polar-optical phonon scattering. At elevated temperatures, the polar-optical phonon dispersion is the predominant process. Yet, at lower temperatures, the IFR and alloy disorder dispersion both satisfactorily account for the reported mobilities.

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Section: Design Parametersmentioning

confidence: 99%

Exploring the impact of AlGaN barrier thickness and temperature on normally-on GaN HEMT performance

Hidayat,

Usman

2024

Eng. Res. Express

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“…It is observed that the device characteristics degrade substantially for thicknesses smaller than ≈100 μm. [ 22 ]…”

Section: Introductionmentioning

confidence: 99%

Asymmetric Gate and SiC Substrate Grooved InGaN Back‐Barrier AlGaN/GaN HEMTs for High‐Power RF Applications

Parvez,

Sahu,

Basak

et al. 2024

Physica Status Solidi (a)

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We report high‐power InGaN back‐barrier AlGaN/GaN high electron mobility transistors with the gate placed closer to the source with an Au‐filled groove in the SiC substrate near the drain end. An InGaN back‐barrier is known to reduce short‐channel effects at high drain‐to‐source (VDS) voltage. However, the improvement is realized at the cost of reduced two‐dimensional electron gas density (ns) and saturation drain‐to‐source (IDS,SAT) current. Here, we demonstrate that both ns and IDS,SAT are recovered when the gate is appropriately delineated near the source. The junction temperature increases at higher VDS, which tends to deteriorate the power performance and suppress the benefits from higher IDS,SAT. This problem is contained by further thinning down the SiC substrate near the drain by creating a backside groove using deep reactive‐ion‐etching and filling it with Ti/Au. An enhanced thinned‐down substrate distributes the lateral electric field uniformly near the drain end, compounding its benefits with an asymmetric gate and lower junction temperature. The proposed device shows an output power of Pout = 6.7 W mm−1 at VDS = 28 V at 15 GHz for a 200 nm gate length (LG).

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High-efficiency green machining of single crystal 4H–SiC based on tribo-oxidation

Wu,

Zhang,

Wang

et al. 2024

Ceramics International

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Improvements From SiC Substrate Thinning in AlGaN/GaN HEMTs: Disparate Effects on Contacts, Access and Channel Regions

Cited by 6 publications

References 18 publications

Exploring the impact of AlGaN barrier thickness and temperature on normally-on GaN HEMT performance

Exploring the impact of AlGaN barrier thickness and temperature on normally-on GaN HEMT performance

Asymmetric Gate and SiC Substrate Grooved InGaN Back‐Barrier AlGaN/GaN HEMTs for High‐Power RF Applications

High-efficiency green machining of single crystal 4H–SiC based on tribo-oxidation

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