N. Sarazin

AlInN/AlN/GaN HEMT Technology on SiC With 10-W/mm and 50% PAE at 10 GHz

High-frequency high-electron-mobility transistors (HEMTs) were fabricated on AlInN/AlN/GaN heterostructures grown by low-pressure metal-organic chemical vapor deposition on a SiC substrate. The results presented in this letter confirm the high performance that is reachable by AlInN-based technology with an output power of 10.3 W/mm and a power-added efficiency of 51% at 10 GHz with a gate length of 0.25 ¿m. A good extrinsic transconductance value that is greater than 450 mS/mm and exceeding AlGaN/GaN HEMT results was also measured on these transistors. To our knowledge, these results are the best power results published on AlInN/GaN HEMTs. These good results were attributed to optimized heterostructure properties associated with low-resistance ohmic contacts and an effective passivation layer minimizing drain current slump in high-frequency operations.

State of the Art 58W, 38% PAE X-Band AlGaN/GaN HEMTs Microstrip MMIC Amplifiers

This paper presents the results obtained on X-Band GaN MMICs developed in the frame of the Kerrigan project launched by the European Defense Agency. A new step was achieved, 58 W of output power with 38% PAE in X-Band were obtained using an 18 mm 2 2-stages amplifier. To our knowledge, these results present a new state-of-the-art of X-Band MMIC power amplifiers.

43W, 52% PAE X-Band AlGaN/GaN HEMTs MMIC Amplifiers

This paper presents the results obtained on X-Band GaN MMICs developed in the frame of the Korrigan project launched by the European Defense Agency. GaN has already demonstrated excellent output power levels, nevertheless demonstration of excellent PAE associated to very high power in MMIC technology is still challenging. In this work, we present State-of-the-Art results on AlGaN/GaN MMIC amplifiers. An output power of 43W with 52% of PAE was achieved at 10.5 GHz showing that high power associated with high PAE can be obtained at X-band using MMIC GaN technology.

Experimental investigation of transparent silicon carbide for atom chips

We investigate some properties of an atom chip made of a gold microcircuit deposited on a transparent silicon carbide substrate. A favorable thermal behavior is observed in the presence of electrical current, twice as good as a silicon counterpart. We obtain one hundred million rubidium atoms in a magneto-optical trap with several of the beams passing through the chip. We point out the importance of coating of the chip against reflection to avoid a temperature-dependent Fabry-Perot effect. We finally discuss detection through the chip, potentially granting large numerical apertures, as well as some other potential applications.

Electrical performances of AlInN/GaN HEMTs. A comparison with AlGaN/GaN HEMTs with similar technological process

A study of the electrical performances of AlInN/GaN High Electron Mobility Transistors (HEMTs) on SiC substrates is presented in this paper. Four different wafers with different technological and epitaxial processes were characterized. Thanks to intensive characterizations as pulsed-IV, [S]-parameters, and load-pull measurements from S to Ku bands, it is demonstrated here that AlInN/GaN HEMTs show excellent power performances and constitute a particularly interesting alternative to AlGaN/GaN HEMTs, especially for high-frequency applications beyond the X band. The measured transistors with 250 nm gate lengths from different wafers delivered in continuous wave (cw): 10.8 W/mm with 60% associated power added efficiency (PAE) at 3,5 GHz, 6.6 W/mm with 39% associated PAE at 10.24 GHz, and 4.2 W/mm with 43% associated PAE at 18 GHz.

InAlN/GaN heterostructures for microwave power and beyond

InAlN/GaN is indeed an alternative to the common AlGaN/GaN heterostructure in electronics and sensing. It enables operation at extremely high temperature once problems with contact metallization and passivation have been solved. It is the only heterostructure known presently, which allows overgrowth of high quality diamond films to combine two of the most stable semiconductors. Thus, applications reach from high power microwaves systems and high temperature electronics to sensing in harsh environment.

First demonstration of AlInN/GaN HEMTs amplifiers at K band

AlInN/GaN HEMTs have shown outstanding power performances for high frequency applications, due in particular to their high current densities and their thinner barrier layers than in AlGaN/GaN HEMTs that minimize short channel effects. In this paper, we present the first published power results of two K-band hybrid amplifier demonstrators at 20GHz and 26.5GHz using 0.25µm gate length devices. At these frequencies, respectively, cw RF output power of 4.5 Watts with 20% PAE and 1.65 W with 15.5 % of PAE were obtained. These state-of-the-art results confirm the potential of AlInN/GaN technology for high frequency applications.

Development of InAlN/GaN HEMTs Power Devices in S-Band

We report on AlInN/GaN HEMTs fabricated using 0.7µm gate length on SiC substrate by Low Pressure Metal Organic Vapor Phase Epitaxy. Static and pulsed DC characteristics show a maximum dc transconductance of 275mS/mm and drain current of 0.9A/mm. Small signal characterizations show Ft and Fmag of 15 and 40 GHz respectively. Load-pull power measurements were performed at S-Band. At 3.5 GHz, an output power of 13W (41.2dBm) corresponding to 6.6W/mm of power density with a PAE of 70% is reached in pulse mode on 2mm devices. 19.2mm power dies allow us to achieve an output power of 56W with 54% of PAE at 2 GHz. To our knowledge, this result represents the highest output power ever reported for AlInN-based HEMT technology.

160W InAlN/GaN HEMTs Amplifier at 2 GHz with Optimized Thermal Management

We report on the realization and measurements of InAlN/GaN HEMTs on SiC substrate. At device level, load-pull power measurements were performed at 2 GHz on 2.2mm devices in CW mode. An output power of 10.5W (40.2dBm) with a PAE of 53% were reached. Then, an amplifier was realized using 36mm power die. Thanks to an optimized thermal management, the amplifier allows us to reach an output power of 160W in pulse mode and 105W in CW. To our knowledge, these results represent the highest output powers ever reported for InAlN/GaN HEMT technology.