Two-step surface-treatment is introduced to obtain low resistance Pt contacts to p-type GaN. The first step is performed after the mesa etching process using buffered oxide etch (BOE) and ammonium sulfide [(NH 4)2Sx]. This is followed by the second step using BOE. The Pt contact, which was treated sequentially using ultrasonically boiled BOE (10 min) and boiled (NH4)2Sx (10 min), produces a specific contact resistance of 3.0 (±3.8)×10 -5 Ωcm2. However, the contact, that was simply BOE-treated, yields 3.1 (±1.1)×10-2 Ωcm 2. This indicates that the two-step surface treatment is promising technique for obtaining high quality ohmic contacts to p-GaN. Investigation of the electronic transport mechanisms using current-voltage-temperature (I-V-T) data indicates that thermionic field emission is dominant in the surface-treated Pt contacts.
|Journal||MRS Internet Journal of Nitride Semiconductor Research|
|Issue number||SUPPL. 1|
|Publication status||Published - 2000 Dec 1|
ASJC Scopus subject areas
- Materials Science(all)