Electrical and structural characterizations of BGaN thin films grown by metal‐organic vapor‐phase epitaxy

Abstract

In this report, the electrical and structural properties of BGaN thin films, with boron composition up to 2%, have been investigated. The resistivity, Hall mobility and carrier concentration were measured by the van der Pauw/Hall Effect technique, using annealed indium ohmic contacts. The current‐voltage measurements between two planar gold and titanium/aluminum electrodes were performed. To analyze the structural properties, the polarized Raman spectra were measured with a micro‐Raman spectrometer. The resistivity displays a strong increase with respect to the boron composition in BGaN alloy, directly related to the decrease of the n‐type carrier concentration, while the mobility increases with boron content, well correlated to the structural measurements showing a good crystalline quality of the BGaN layers. This boron‐controlled resistivity is very promising for using the BGaN based materials in microelectronic and optoelectronic devices. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Solar blind metal-semiconductor-metal ultraviolet photodetectors using quasi-alloy of BGaN/GaN superlattices

“…To achieve this purpose, semi-insulating iron-doped GaN from one part, and BGaN monolayer, and quasi-alloy of BGaN/GaN from the other part were used as active layers. Indeed, as we have shown previously, 18 the electrical conductivity of the BGaN alloy can be tuned over more than seven orders of magnitude using low boron incorporation concentration (less than 2%).…”

Neutron detection using boron gallium nitride semiconductor material

“…[19][20][21] On the other hand, the BGaN crystal growth techniques for ultraviolet LED have been studied. [22][23][24][25][26][27][28] In the low B composition (less than 3.6%) region, the fabrication of BGaN alloy crystal, by the substitution of B with Ga in the GaN, was realized. [22][23][24][25] Previous studies for BGaN evaluated the optical 26 and the electrical properties, 27 and bowing parameter was calculated.…”

Device characteristics of enhancement mode double heterostructure DH‐HEMT with boron‐doped GaN gate cap layer for full‐bridge inverter circuit

“…Figure shows the comparison and variation of I ds,sat and g m values for B‐doped and Mg‐doped GaN cap DH‐HEMT extracted from I ds ‐V gs transfer characteristics of the devices for various Al content “x” in Al x Ga 1‐x N back‐barrier/buffer. The B‐doped GaN cap device exhibited highest current density (from I ds,sat = 0.6 A/mm with x = 0% to 0.27 A/mm with x = 7%) in the illustrated Al content range “x” in Al x Ga 1‐x N buffer; by contrast, the Mg‐doped GaN cap device exhibited a drop in current density (from I ds,sat = 0.3 A/mm with x = 0% to 0.12 A/mm with x = 7%) at a drain bias of 15 V. Because of the high resistive and low carrier trapping effect, the B‐doped GaN cap device achieved relatively both high ON‐state I ds,sat and peak g m and exhibited a much lower OFF‐state leakage current, indicating that this architecture provided the device with effective channel modulation than that of the Mg‐doped GaN cap device.…”

“…Therefore, enhancing V BR,OFF and V T is one of the most significant challenges in the evolution of GaN‐based efficient power switches . While, both aspects still need the consideration by researchers, certainly, obtaining enhancement mode (E‐mode) behavior in GaN‐based devices with sufficiently high V T has always been a struggle . Several approaches, such as high Al content channels or the use of quaternary barriers to allow a zero polarization difference at the barrier/channel interface, cap layer doping under the gate (p‐InGaN, p‐AlGaN), and recessed gate etching techniques have been implemented to achieve the E‐mode AlGaN/GaN HEMTs.…”

“…However, the reported devices and GaN‐based cap gate HEMTs show drawbacks such as low I ON , V T , high gate and drain leakage currents, and low V BR,OFF. Thus, in order to overcome the current drawbacks of GaN‐cap HEMTs, it is crucial to achieve a much higher value of V T than the reported data for safe E‐mode operation of low‐power consumption, circuit simplicity, and fail‐safe requirements. In this respect, boron (B) or magnesium (Mg) doped GaN cap‐layer is used under the gate to achieve high V T , low‐leakage, and high V BR,OFF DH‐HEMT devices.…”