Self-aligned-gate AlGaN/GaN heterostructure field-effect transistor with titanium nitride gate

Zhang, Jiaqi; Wang, Lei; Li, Liuan; Wang, Qingpeng; Jiang, Ying; Zhu, Huichao; Ao, Jin‐Ping

doi:10.1088/1674-1056/25/8/087308

Cited by 3 publications

(2 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…More device-level methods concentrate on the improvements of g m flatness to achieve a large GVS. Previously, many simple methods were proposed to improve the g m flatness, such as the field plate reducing the channel electric field [64] , the self-aligned source and drain eliminating the access resistance [65,66] , the optimization of some structure parameters [67,68] . However, the effect of these methods seems to be not satisfied with the current requirements.…”

Section: Improvement Methods Of Transconductancementioning

confidence: 99%

A review on GaN HEMTs: nonlinear mechanisms and improvement methods

Du,

Ye,

Cai

et al. 2023

J. Semicond.

View full text Add to dashboard Cite

The GaN HEMT is a potential candidate for RF applications due to the high frequency and large power handling capability. To ensure the quality of the communication signal, linearity is a key parameter during the system design. However, the GaN HEMT usually suffers from the nonlinearity problems induced by the nonlinear parasitic capacitance, transconductance, channel transconductance etc. Among them, the transconductance reduction is the main contributor for the nonlinearity and is mostly attributed to the scattering effect, the increasing resistance of access region, the self-heating effect and the trapping effects. Based on the mechanisms, device-level improvement methods of transconductance including the trapping suppression, the nanowire channel, the graded channel, the double channel, the transconductance compensation and the new material structures have been proposed recently. The features of each method are reviewed and compared to provide an overview perspective on the linearity of the GaN HEMT at the device level.

show abstract

Section: Improvement Methods Of Transconductancementioning

confidence: 99%

A review on GaN HEMTs: nonlinear mechanisms and improvement methods

Du,

Ye,

Cai

et al. 2023

J. Semicond.

View full text Add to dashboard Cite

show abstract

“…Self-aligned gate (SAG) structure is an effective method to minimize the access region (access resistance) of AlGaN/GaN HFETs, which is beneficial for achieving higher f T . [3] In a SAG structure, the Schottky gate serves as mask for ohmic electrode deposition and anneals simultaneously with ohmic electrodes. The widely used Ti/Al-based multilayers on AlGaN/GaN HFETs need a high annealing temperature (commonly above 700 • C) to form ohmic contact, which usually causes a high gate leakage current of the Schottky contact and degrades the noise handling capacity.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of thermally stable HfO _x N _y as gate dielectric for AlGaN/GaN heterostructure field-effect transistors

Zhang

Xie

et al. 2018

Chinese Phys. B

View full text Add to dashboard Cite

In this paper, we adopted thermally stable HfO x N y as gate dielectric for TiN/HfO x N y /AlGaN/GaN heterostructure field-effect transistors (HFETs) application. It demonstrated that the surface morphologies, composition, and optical properties of the HfO x N y films were dependent on oxygen flow rate in the O 2 /N 2 /Ar mixture sputtering ambient. The obtained metal-oxide-semiconductor heterostructure field-effect transistors by depositing HfO 2 and HfO x N y dielectric at different oxygen flow rates possessed a small hysteresis and a low leakage current. After post deposition annealing at 900 • C, the device using HfO x N y dielectric operated normally with good pinch-off characteristics, while obvious degradation are observed for the HfO 2 gated one at 600 • C. This result shows that the HfO x N y dielectric is a promising candidate for the self-aligned gate process.

show abstract

Surface morphology improvement of homoepitaxial GaN grown on free-standing GaN substrate by metalorganic chemical vapor deposition

Li¹,

Luo²,

Yang³

et al. 2017

Acta Phys. Sin.

View full text Add to dashboard Cite

Free-standing GaN is generally regarded as an ideal substrate for GaN-based devices due to its advantage of low threading dislocation density (TDD) and good thermal conductivity. However, new surface features such as hillocks and ridges appear on the GaN homoepitaxy films. In this paper, the influences of the intermediate GaN (IM-GaN) layer on the surface defects and crystal quality of GaN homoepitaxy films grown on c-plane GaN substrates by metalorganic chemical vapor deposition are investigated. It is found that hexagonal hillocks and ridges on the surface can be avoided by inserting an IM-GaN layer grown at an intermediate temperature (650850℃), prior to the growth of GaN at 1050℃. The results based on X-ray diffraction (XRD) measurements and differential interference contrast microscopy images demonstrate that the growth temperature of the IM-GaN layer has a significant influence on GaN homoepitaxy layer, which is one of the most critical parameters determining the surface morphology and crystal quality. As the IM-GaN growth temperature decreases from 1050℃ to 650℃, thed densities of hillocks and ridges on the surface reduce gradually. While, the XRD full width at half maximum (FWHM) values of (002) and (102) peaks for the homoepitaxy films are increased rapidly, indicating the adding of the TDD in the films. The atomic force microscopy (AFM) images show that the quasi-step growth mode change into layer-layer growth mode with the growth temperature decreasing from 1050℃ to 650℃ during the IM-GaN layer growing. It is speculated that the growth mode is determined by the diffusion length of adatom on the growing surface, which is proportional to the growth temperature. In the case of IM-GaN grown at low temperature, the formation of hillocks can be suppressed by reducing the adatom diffusion length. Finally, High crystal quality GaN homoepitaxy films (2 m) without hillocks is achieved by optimizing the growth parameters of IM-GaN layer, which is about 150 nm in thickness and grown at 850℃. The crystal quality of GaN homoepitaxy film is assessed by XRD rocking curve measured with double-crystal optics. The FWHMs of the (002) and (102) peaks are 125arcsec and 85arcsec respectively, indicating that rather low TDD is formed in the film. And well defined steps are observed on the image of AFM test, the root-mean square roughness value of the which is only about 0.23 nm for 5 m5 m scan area.

show abstract

Self-aligned-gate AlGaN/GaN heterostructure field-effect transistor with titanium nitride gate

Cited by 3 publications

References 12 publications

A review on GaN HEMTs: nonlinear mechanisms and improvement methods

A review on GaN HEMTs: nonlinear mechanisms and improvement methods

Synthesis of thermally stable HfO _x N _y as gate dielectric for AlGaN/GaN heterostructure field-effect transistors

Surface morphology improvement of homoepitaxial GaN grown on free-standing GaN substrate by metalorganic chemical vapor deposition

Contact Info

Product

Resources

About

Self-aligned-gate AlGaN/GaN heterostructure field-effect transistor with titanium nitride gate

Cited by 3 publications

References 12 publications

A review on GaN HEMTs: nonlinear mechanisms and improvement methods

A review on GaN HEMTs: nonlinear mechanisms and improvement methods

Synthesis of thermally stable HfO x N y as gate dielectric for AlGaN/GaN heterostructure field-effect transistors

Surface morphology improvement of homoepitaxial GaN grown on free-standing GaN substrate by metalorganic chemical vapor deposition

Contact Info

Product

Resources

About

Synthesis of thermally stable HfO _x N _y as gate dielectric for AlGaN/GaN heterostructure field-effect transistors