Etched-And-Regrown GaN P–N Diodes with Low-Defect Interfaces Prepared by In Situ TBCl Etching

Abstract

The ability to form pristine interfaces after etching and regrowth of GaN is a prerequisite for epitaxial selective area doping, which in turn is needed for the formation of lateral PN junctions and advanced device architectures. In this work, we report the electrical properties of etched-and-regrown GaN PN diodes using an in situ Cl-based precursor, tertiary butylchloride (TBCl). We demonstrated a regrowth diode with I−V characteristics approaching that from a continuously grown reference diode. The sources of unintentional contamination from the silicon (Si) impurity and the mediating effect of Si during the TBCl etching are also investigated in this study. This work points to the potential of in situ TBCl etching toward the realization of GaN lateral PN junctions.

Effect of Sintering Temperature on Microstructure and Mechanical Properties of Fe–4Ni–0.8Mo–0.6C Steel Small‐Module Gears Fabricated by Micrometal Injection Molding

“…Recent research surveyed that both low viscosity and low activation energy are required for successful mold filling, especially in complex geometry injection molds. [ 26 ] It should be noted that the feedstock having higher values of moldability index has more appropriate and stable behavior during mold filling.…”

Selective area doping of GaN toward high-power applications

“…However, HCl is a corrosive gas and not normally compatible with MOCVD hardware. Recently, Li et al [75][76][77][78] explored the use of a Clbased organometallic precursor, tertiarybutyl-chloride (TBCl), in MOCVD and performed both planar and SAE of GaN. In previous studies of in situ etching of gallium arsenide (GaAs) and indium phosphide (InP), TBCl was found to be compatible with the MOCVD apparatus [79][80][81].…”

“…The PL measurement, presented in figure 3(a), indicates that TBCl etching is a lowdamage etching process and capable of removing ICP-induced damage, because both TBCl and ICP + TBCl samples exhibited a strong NBE [76]. Planar p-n diodes were prepared with the regrowth interface buried 300 nm below the metallurgical p-n junction [77]. The lowest leakage current was observed in the TBCl-etched device, as shown in figure 3(b), which further corroborates the claim that TBCl introduces much less damage.…”

(Invited) Selective Area Etching and Doping of GaN for High-Power Applications

“…Selective-area etching experiments were performed on GaN-on-sapphire samples With a successive reduction of the NH 3 flow rate and the reactor pressure, pyramids disappear and a smooth surface is achieved with 14 sccm of NH 3 and 2.5 sccm of TBCl at 800°C and 50 mbar. The presence of those pyramids can be attributed to the low desorption rate of species (GaCl x or impurities from ex-situ process 11,16 ), sometimes this micro-masking effect inhibits etching process locally. A lower NH 3 flow rate and reactor pressure facilitate the desorption process, and therefore it leads to a smooth surface.…”

“…A combination of ICP and TBCl etching results in the worst reverse characteristics among the four devices. The reason for the deterioration of device performance (device C) compared to device B or D is due to the complication of the TBCl etching process with the presence of impurities, such as Si and Al, 11,16 though the damage and some impurities could be removed by TBCl as mentioned above. Detailed analysis and reasoning will be reported elsewhere.…”