Search

For 1-kV 30-A 411-SiC epitaxial emitter n-p-n bipolar junction transistors, the dependences of the common-emitter current gain βCE on the collector current 1C were measured at elevated temperatures. The collector-emitter voltage was fixed (at 100 V) to provide an active operation mode at all collector currents varying in a wide range from 150 mA to 40 A (current densities of 24-6350 A/cm2). The maximum current gain was measured to be βCEmax = 40(IC = 7 A) at room temperature and βCEmax = 32(IC = 10 A) at 250 °C. The βCE-IC dependences were simulated in terms of a model that takes into account the main processes affecting the current gain: 1) recombination in the emitter-base space charge region; 2) surface recombination; 3) crowding of the emitter current; 4) decrease in the emitter-injection coefficient at high-level injection; and 5) ionization of deep acceptors. The minority carrier lifetimes and surface recombination velocity were obtained by means of this simulation. [ABSTRACT FROM AUTHOR]

Planar 4H-SiC accumulation channel field effect transistor (ACCUFET) have been designed, fabricated, and characterized. Detailed design and processing experiments were conducted on relatively large area ACCUFETs to boost their power ratings. A detailed two-dimensional (2-D) simulation design suggests that the optimum spacing between two adjacent p+ regions is approximately 4 µm. A novel process with epitaxial regrowth over ion implanted p+ base region was developed to achieve a high accumulation layer mobility. Process splits from nitrogen-rich post gate oxidation anneals revealed that the lowest on-resistance and optimum threshold voltage were obtained from N[sub 2]O annealed samples. 550 V blocking voltage with 22 mΩ-cm² were demonstrated on 2 A 4H-SiC ACCUFETs. Using a newly developed hex-gate design, larger, 20 A 4H-SiC ACCUFETs are presented here with stable high temperature characteristics. In these high-current devices, the threshold voltage decreases linearly from 1.5 V to 0.9 V, while the extracted channel mobility increases from 18 cm²/V-s to 33.6 cm²/V-s as the operating temperature is increased from 30 °C to 200 °C. [ABSTRACT FROM AUTHOR]

Reviews the development of silicon carbide (SiC) electronic device technology. Critical fabrication issues regarding the device; Challenges in the fabrication of SiC devices; Significance of the high thermal and chemical stability of SiC.