GaN Nitride Semiconductor Leakage Current Reduction

The patent applies preliminary action by performing a nitrogen supply treatment (such as nitrogen plasma treatment or deposition of nitrogen-containing film) on the GaN surface before performing dry etching to form the mesa-like laminated portion. This preliminary nitrogen supply prevents nitrogen atoms from being removed during etching, thereby preventing formation of nitrogen vacancies while still allowing precise structural definition through etching.

The patent uses beforehand cushioning by introducing a nitrogen-containing protective layer or performing nitrogen plasma treatment prior to dry etching. This cushioning layer protects the GaN crystal lattice from nitrogen depletion during the etching process, preventing formation of nitrogen vacancies that would otherwise occur at the etched surfaces.

The patent converts the harmful effect of nitrogen vacancies into a beneficial outcome by using nitrogen-containing insulating materials (such as silicon nitride) that not only prevent nitrogen vacancy formation but also actively supply nitrogen to compensate for any vacancies. The nitrogen-containing film transforms the potential harm of nitrogen depletion into a benefit by creating a nitrogen-rich environment that eliminates nitrogen vacancies and reduces surface leakage current.

The patent applies parameter changes by modifying the chemical composition and nitrogen concentration at the GaN surface through deposition of nitrogen-containing insulating films or nitrogen plasma treatment. By changing the nitrogen concentration parameter from deficient (vacancy-prone) to excess (nitrogen-rich), the surface level density is controlled and surface leakage current is reduced.