This letter describes a new two-step electrode process on p-GaN and characteristics of GaN p-n junction diodes on free-standing GaN substrates with low specific on-resistance Formula Omitted and high ...breakdown voltage Formula Omitted. We develop a two-step process for anode electrodes in order to avoid plasma damage to the Formula Omitted-GaN contact layer during the sputtering process. The specific on-resistance is further improved due to a new low-damage process. The breakdown voltage of the diodes with the field-plate (FP) structure is over 1100 V, and the leakage current was low, i.e., in the range of Formula Omitted. The specific on-resistance of the diodes of 50 Formula Omitted in diameter with the FP structure was 0.4 Formula Omitted. Baliga's figure of merit Formula Omitted of 3.0 Formula Omitted is obtained. These are the best values ever reported among those achieved by GaN p-n junction diodes on free-standing GaN substrates.
We demonstrate Si ion-implanted GaN/AlGaN/GaN high-electron mobility transistors with extremely low gate leakage current and low source resistance without any recess etching process. The source/drain ...(S/D) regions were formed using Si ion implantation into undoped GaN/AlGaN/GaN on sapphire substrate. Using ion implantation into S/D regions with an energy of 80 keV, the performances were significantly improved. On-resistance decreased from 26.2 to 4.3 Omega ldr mm. Saturation drain current and maximum transconductance increased from 284 to 723 mA/mm and from 48 to 147 mS/mm.
A novel microfabrication method of lead-free piezoelectric sodium potassium niobate (K,Na)NbO sub(3, KNN thin films was proposed, and the piezoelectric characteristics of the KNN microactuators were ...evaluated. The KNN thin films were directly deposited on microfabricated Si microcantilevers. The transverse piezoelectric coefficient d) sub(3)1 of the KNN films was calculated as -53.5 pm/V at 20 V sub(pp from the tip displacement of the microcantilevers. However, the tip displacement showed large electric-field dependence because of the extrinsic piezoelectric effect, and the intrinsic piezoelectric effect of the KNN microcantilevers was smaller than that of KNN on unprocessed thick substrates. In contrast, the extrinsic piezoelectric effect was almost independent of the microfabrication of the KNN films.)
![Over 3.0 [Formula Omitted] ...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0741-3106/small "Over 3.0 [Formula Omitted] Figure-of-Merit GaN p-n Junction Diodes on Free-Standing GaN Substrates")
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