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Demonstration of normally-off p-channel GaN transistor with high threshold voltage and low subthreshold swing based on single p-GaN

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Science China(Information Sciences) 2024年第9期67卷 348-349页

作者： Yangfeng LI Zian DONG Shuai CHEN Qin WANG Tong LI Shulin CHEN Kun ZHENG Jie ZHANG Guojian DING Yang WANG haiqiang jia Rong YANG Lei LIAO Changsha Semiconductor Technology and Application Innovation Research Institute College of Semiconductors (College of Integrated Circuits) Hunan University Hunan San'an Semiconductor Co. Ltd. Songshan Lake Materials Laboratory

GaN outperforms silicon in applications with high power and high frequency owing to the high critical electric field and high electron mobility. However, the hole-based GaN transistors which are pivotal to the GaN-based CMOS circuits and high-side switching are still under investigation. Two-dimensional hole gas(2DHG) has been used to demonstrate the p-channel GaN field-effect-transistors(FETs) [1–5].

关键词： MOSFETS

Reanalysis of energy band structure in the type-II quantum wells

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Chinese Physics B 2024年第6期33卷 75-78页

作者：李欣欣邓震江洋杜春花贾海强王文新陈弘 Key Laboratory for Renewable Energy Beijing Key Laboratory for New Energy Materials and DevicesBeijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing 100190China Center of Materials and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China The Yangtze River Delta Physics Research Center Liyang 213000China Songshan Lake Materials Laboratory Dongguan 523808China

Band structure analysis holds significant importance for understanding the optoelectronic characteristics of semiconductor structures and exploring their potential applications in practice. For quantum well structures, the energy of carriers in the well splits into discrete energy levels due to the confinement of barriers in the growth direction. However, the discrete energy levels obtained at a fixed wave vector cannot accurately reflect the actual energy band structure. In this work, the band structure of the type-II quantum wells is reanalyzed. When the wave vectors of the entire Brillouin region(corresponding to the growth direction) are taken into account, the quantized energy levels of the carriers in the well are replaced by subbands with certain energy distributions. This new understanding of the energy bands of low-dimensional structures not only helps us to have a deeper cognition of the structure, but also may overturn many viewpoints in traditional band theories and serve as supplementary to the band theory of low-dimensional systems.

关键词： energy band structure type-II quantum wells low-dimensional semiconductors

Characterization of the N-polar GaN film grown on C-plane sapphire and misoriented C-plane sapphire substrates by MOCVD

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Chinese Physics B 2022年第3期31卷 134-139页

作者： Xiaotao Hu Yimeng Song Zhaole Su haiqiang jia Wenxin Wang Yang jiang Yangfeng Li Hong Chen Key Laboratory for Renewable Energy Beijing Key Laboratory for New Energy Materials and DevicesBeijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Songshan Lake Materials Laboratory Dongguan 523808China School of Mathematics and Physics Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface ScienceUniversity of Science and Technology BeijingBeijing 100083China College of Materials Science and Opto-Electronic Technology University of Chinese Academy of SciencesBeijing 100049China

Gallium nitride(GaN) thin film of the nitrogen polarity(N-polar) was grown on C-plane sapphire and misoriented C-plane sapphire substrates respectively by metal-organic chemical vapor deposition(MOCVD). The misorientation angle is off-axis from C-plane toward M-plane of the substrates, and the angle is 2°and 4°respectively. The nitrogen polarity was confirmed by examining the images of the scanning electron microscope before and after the wet etching in potassium hydroxide(KOH) solution. The morphology was studied by the optical microscope and atomic force microscope. The crystalline quality was characterized by the x-ray diffraction. The lateral coherence length, the tilt angle, the vertical coherence length, and the vertical lattice-strain were acquired using the pseudo-Voigt function to fit the x-ray diffraction curves and then calculating with four empirical formulae. The lateral coherence length increases with the misorientation angle, because higher step density and shorter distance between adjacent steps can lead to larger lateral coherence *** tilt angle increases with the misorientation angle, which means that the misoriented substrate can degrade the identity of crystal orientation of the N-polar GaN film. The vertical lattice-strain decreases with the misorientation angle. The vertical coherence length does not change a lot as the misorientation angle increases and this value of all samples is close to the nominal thickness of the N-polar GaN layer. This study helps to understand the influence of the misorientation angle of misoriented C-plane sapphire on the morphology, the crystalline quality, and the microstructure of N-polar GaN films.

关键词： metal-organic chemical vapor deposition(MOCVD) misoriented sapphire substrate misorientation angle x-ray diffraction N-polar GaN

The influence of pressure on the growth of a-plane GaN on r-plane sapphire substrates by MOCVD

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Science China(Physics,Mechanics & Astronomy) 2011年第3期54卷 446-449页

作者： HE Tao LI Hui DAI LongGui WANG XiaoLi CHEN Yao MA ZiGuang XU PeiQiang jiaNG Yang WANG Lu jia haiqiang WANG WenXin CHEN Hong Beijing National Laboratory of Condensed Matter Institute of Physics Chinese Academy of Sciences Beijing 100190 China

Nonpolar a-plane （1120） GaN films have been grown on r-plane （1102） sapphire by metal-organic chemical vapor deposition （MOCVD） under different growth pressures. The as-grown films are investigated by optical microscopy, high-resolution X-ray diffraction （HRXRD） and Raman scattering. As growth pressure rises from 100 mbar to 400 mbar, the surface gets rougher, and the in-plane XRD full width at half maximum （FWHM） along the c-axis [0001] increases while that along the m-axis [1100] decreases. Meanwhile, residential stresses are reduced along both the c-axis and the m-axis. The structural anisotropy feature under 400 mbar is inverted with respect to 100 mbar, and the weakened anisotropy is achieved under a moderate pressure of 200 mbar, probably due to the suppressed Ga atomic migration along the c-axis under a larger pressure. We propose that pressure can affect a-plane growth through the V/III ratio.

关键词： GaN anisotropy XRD growth pressure MOCVD

The impact of nanoporous SiN_x interlayer growth position on high-quality GaN epitaxial films

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Chinese Science Bulletin 2011年第25期56卷 2739-2743页

作者： MA ZiGuang XING ZhiGang WANG XiaoLi CHEN Yao XU PeiQiang CUI YanXiang WANG Lu jiaNG Yang jia haiqiang CHEN Hong Beijing National Laboratory of Condensed Matter Institute of Physics Chinese Academy of Sciences Beijing 100190 China

The impact of nanoporous SiN x interlayer growth position on high-quality GaN epitaxial film was elucidated from the behavior of dislocations. The best quality GaN film was achieved when a nanoporous SiN x interlayer was grown on a rough layer, with the high-resolution X-ray diffraction rocking curve full width at half maximum for ( 1102 ) reflection decreasing to 223 arcs, and the total dislocation density reduced to less than 1.0×10 8 cm 2 . GaN films were grown on sapphire substrates by metal organic chemical vapor deposition. The quality of these films was investigated with high-resolution X-ray diffraction, atomic force microscopy, and cross-sectional transmission electron microscopy. A preference for the formation of half-loops to reduce threading dislocations was observed when an SiN x interlayer was grown on a rough layer. A growth mechanism is proposed to explain this preference.

关键词：氮化硅外延片多孔层间氮化镓 GaN薄膜化学气相沉积法透射电子显微镜

Recent progress in single chip white light-emitting diodes with the InGaN underlying layer

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Science China(Physics,Mechanics & Astronomy) 2010年第3期53卷 445-448页

作者： WANG XiaoLi, WANG XiaoHui, jia haiqiang, XING ZhiGang & CHEN Hong Beijing National Laboratory of Condensed Matter, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China Beijing National Laboratory of Condensed Matter Institute of Physics Chinese Academy of Sciences Beijing China

Tremendous progress has been achieved in white light-emitting diodes (LEDs). To further improve the quality of white light and simplify the fabrication process, a single chip white-light LED with the InGaN underlying layer (UL) was studied and fabricated. The turn-on voltage of this type of LED was 2.7 V, and the spectrum at a forward bias current of 20 mA was comprised of blue (443 nm) and yellow (563 nm) lights. The intensity ratio of blue to yellow light was almost constant with the in- creasing injection current in a certain scope, most important for the solid state illumination. The useful life test showed the light output level remained at a 90% light output level at the driving current of 40 mA after 300 h, meanwhile, the UV and blue LEDs combined with phosphor reached a 20% value after 144 h within 300 h.

关键词： GaN InGaN white light LED MOCVD

Effect of Pt Interlayer on Low Resistivity Ohmic Contact to p-InP Layer and Its Optimization

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Chinese Physics Letters 2021年第6期38卷 72-75页

作者： Lili Han Chunhua Du Ziguang Ma Yang jiang Kanglin Xiong Wenxin Wang Hong Chen Zhen Deng haiqiang jia Key Laboratory for Renewable Energy Beijing Key Laboratory for New Energy Materials and DevicesBeijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Center of Materials and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Songshan Lake Materials Laboratory Dongguan 523808China The Yangtze River Delta Physics Research Center Liyang 213000China NANO-X Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123China

The contact characteristic between p-InP and metal plays an important role in InP-related optoelectronic and microelectronic device *** investigate the low-resistance Au/Pt/Ni and Au/Ni ohmic contacts to p-InP based on the solid phase regrowth *** lowest specific contact resistivity of Au(100 nm)/Pt(115 nm)/Ni(50 nm)can reach 2.64×10^(-6)Ω·cm^(2) after annealing at 380℃ for 1 min,while the contact characteristics of Au/Ni deteriorated after annealing from 340℃ to 480℃ for 1 *** results of scanning electron microscopy,atomic force microscopy and x-ray photoelectron spectroscopy show that the Pt layer is an important factor in improving the contact *** Pt layer prevents the diffusion of In and Au,inhibits the formation of Au3In metal compounds,and prevents the deterioration of the ohmic *** metal structures and optimized annealing process is expected to be helpful for obtaining high-performance InP-related devices.

关键词： resistance annealing Resistivity

Characteristics of AlGaN/GaN high electron mobility transistors on metallic substrate

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Chinese Physics B 2020年第4期29卷 512-515页

作者： Minglong Zhao Xiansheng Tang Wenxue Huo Lili Han Zhen Deng Yang jiang Wenxin Wang Hong Chen Chunhua Du haiqiang jia Key Laboratory for Renewable Energy Beijing Key Laboratory for New Energy Materials and DevicesBeijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Center of Materials and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Songshan Lake Materials Laboratory Dongguan 523808China The Yangtze River Delta Physics Research Center Liyang 213000China

We have successfully prepared GaN based high electron mobility transistors(HEMTs)on metallic substrates transferred from silicon substrates by electroplating *** HEMTs on Cu substrates are demonstrated to basically have the same good electric characteristics as the chips on Si ***,the better heat dissipation of HEMTs on Cu substrates compared to HEMTs on Si substrates is clearly observed by thermoreflectance imaging,showing the promising potential for very high-power and high-temperature *** work shows the outstanding ability of HEMT chips on Cu substrates for solving the self-heating effect with the advantages of process simplicity,high yield,and low production requirement.

关键词： GaN high electron mobility transistor(HEMT) electric characteristics electroplating heat dissipation

Sphere-shaped SiGe micro/nanostructures with tunable Ge composition and size formed by laser irradiation

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Chinese Physics B 2021年第9期30卷 384-387页

作者： Xinxin Li Zhen Deng Sen Wang Jinbiao Liu Jun Li Yang jiang Ziguang Ma Chunhua Du haiqiang jia Wenxin Wang Hong Chen Key Laboratory for Renewable Energy Beijing Key Laboratory for New Energy Materials and DevicesBeijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Center of Materials and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China The Yangtze River Delta Physics Research Center Liyang 213000China Key Laboratory of Microelectronics Devices and Integrated Technology Institute of MicroelectronicsChinese Academy of SciencesChina Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China.

SiGe spheres with different diameters are successfully fabricated on a virtual SiGe template using a laser irradiation *** results from scanning electron microscopy and micro-Raman spectroscopy reveal that the diameter and Ge composition of the SiGe spheres can be well controlled by adjusting the laser energy *** addition,the transmission electron microscopy results show that Ge composition inside the SiGe spheres is almost uniform in a well-defined,nearly spherical *** a convenient method to prepare sphere-shaped SiGe micro/nanostructures with tunable Ge composition and size,this technique is expected to be useful for SiGe-based material growth and micro/optoelectronic device fabrication.

关键词： SiGe micro/nanospheres laser irradiation