High-breakdown-voltage Ga/sub 0.51/In/sub 0.49/P channel MESFET's grown by GSMBE
The first Ga/sub 0.51/In/sub 0.49/P channel MESFETs grown on a (100) GaAs substrate by GSMBE have been fabricated. A high gate-to-drain breakdown voltage of 42 V with a high maximum current density (320 mA/mm) was achieved. This result demonstrates that high-breakdown voltage could be attained by using Ga/sub 0.51/In/sub 0.49/P as the channel material. We also measured a high-maximum oscillation frequency (f/sub max/) of 30 GHz for a 1.5 /spl mu/m gate-length device. This value is quite high compared with other high-breakdown-voltage GaAs MESFET's or MISFET's with the same gate length.
High-Linearity High-Current-Drivability Gao.5 1 Ino.49P/GaAs MISFET Using Gao.5 1 Ino.49P Airbridge Gate Structure Grown by GSMBE
A novel structure Gao.51 Im.rsP/GaAs MISFET with an undoped Gao.slIno.*eP layer serving as the airbridge between active region and gate pad was first designed and fabricated. Wide and flat characteristics of gm and f max versus drain current or gate voltage were achieved. The device also showed a very high maximum current density (610 mA/mm) and a very high gate-to-drain breakdown voltage (25 V). Parasitic capacitances and leakage currents were minimized by the air- bridge gate structure and thus high f~ of 22 GHz and high f,,, of 40 GHz for 1 pm gate length devices were attained. To our knowledge, both were the best reported values for 1 pm gate GaAs channel FET's.
Coronial Practice, Indigeneity and Suicide
All available data suggest that, like many other Indigenous peoples, Australian Aborigines are significantly more likely to kill themselves than are non-Aboriginal Australians. This statistical disparity is normally positioned an objective, ontological and undeniable social fact, a fact best explained as a function of endemic community disadvantage and disenfranchisement. This research explores the possibility that higher-than-normal Aboriginal suicide rates may also be a function of coronial decision-making practices. Based upon in-depth interviews with 32 coroners from across Australia, the following conclusions emerged from the data. First, coroners have differing perceptions of Indigenous capacity, and are less likely to have concerns about intent when the suicide is committed by an Indigenous person. Second, coroners have identified divergent scripts of Indigenous suicide, particularly its spontaneity and public location, and this supports rather than challenges, a finding of suicide. Third, the coronial perception of Indigenous life is a factor which influences a suicide determination for Indigenous deaths. Finally, the low level of Indigenous engagement with the coronial system, and the unlikelihood of a challenge to the finding of suicide by Indigenous families, means that a coronial determination of suicide is more likely.