Al Ga N ∕ Ga N high electron mobility transistors on Si∕SiO2/poly-SiC substrates

Abstract

Structural and morphological properties of GaN buffer layers grown by ammonia molecular beam epitaxy on SiC substrates for AlGaN/GaN high electron mobility transistors Growth of high mobility GaN and AlGaN/GaN high electron mobility transistor structures on 4H-SiC by ammonia molecular-beam epitaxy AlGaN / GaN high electron mobility transistors were grown by molecular beam epitaxy on Si on poly-SiC substrates formed by the Smart Cut™ process. The Smart Cut™ approach is an alternative solution to provide both a high resistivity and an excellent thermal conductivity template needed for power applications. Although the structure has not been optimized, devices with 0.7 m gate length show breakdown voltage of Ͼ250 V, f T of 18 GHz, and f max of 65 GHz.

Neutron irradiation on AlGaN/GaN high electron mobility transistors on SiC substrates

“…Most of the devices are fabricated on heteroepitaxy grown on sapphire substrates which satisfy both relatively low cost and high quality of epitaxy. However, the use of SiC substrate has advantage over Al 2 O 3 for electronic device applications because of the superior thermal conductivity, which leads less device self-heating and results in improved reliability and operating stability [8]. For AlGaN HEMT microwave power amplifier, self-heating of the device starts to occur at a power density of 5 W/mm and limited rf performance is observed [9,10].…”

Spectroscopic ellipsometry studies of GaN films deposited by reactive rf sputtering of GaAs target

“…[19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] Polycrystalline, 19 nanocrystalline, 20 and amorphous 37 GaN have also shown good luminescence characteristics. Applications of polycrystalline GaN films have been demonstrated in LEDs, 38,39 white lighting, 39 UV photodetectors, 40 solar cells, 41,42 thin film transistors, 43,44 and field electron emitters, 16,45 and suitability of GaN films for application in large area flat panel displays has also been explored. 46 The potential of GaN films for these applications has thus driven the search for low cost and low temperature deposition processes on low cost substrates.…”

Microwave Performance of AlGaN/GaN High-Electron-Mobility Transistors on Si/SiO2/Poly-SiC Substrates

“…[16][17][18][19][20][21] This problem is manifested by a collapse in the drain current or frequency dispersion in transconductance and output resistance, leading to severely reduced output power and power-added efficiency. Several mechanisms have been identified, including the presence of surface states between the gate and drain that deplete the channel in this region with time constant long enough to disrupt modulation of the channel charge during large signal operation or of trap states in the buffer layer.…”

“…Thermal simulations of nitride HEMTs operating at power densities of 5 to 15 W/mm grown on such substrates indicate junction temperatures fairly similar to devices on polycrystalline SiC substrates. 16,17 In this paper, we report on results on the RF performance of AlGaN/GaN HEMTs grown on SopSiC substrates. Devices with a 0.5 lm gate length and gate-to-drain distances of 3 to 32 lm show f T of 18 to 27 GHz and f max of 43 to 47 GHz.…”