Abstract
Two approaches are investigated in order to obtain good stable ohmic contacts to u-type GaN. In the first one the ohmic contact is enabled by depositing W on an n+-GaN region produced by Si implantation. The contacts were RTA treated at 750, 850, 950, and 1050°C for 10 s. The 750, 950 and 1050°C anneals produced good ohmic contacts with contact resistivities ranging from 2.6·10-6 to 1.1·10-4 Ωcm2, as measured by the transmission line model technique, while the 850°C anneal produced leaky rectifying diodes. In the second approach, a graded In1-xAlxN epilayer facilitates the proper band alignment needed for an ohmic contact. In order to test the feasibility of this approach a stack of 500 angstrom W/500 angstrom WSi/3500 angstrom n+-In1-xAlxN/AlN with x = 0, 0.27 and 0.46 was deposited on sapphire and RTA treated at temperatures up to 700°C. Contact resistivity values of 1·10-6 to 1·10-5 Ωcm2 were obtained. The contact resistivity increased as the annealing temperature increased.
| Original language | English |
|---|---|
| Pages (from-to) | 358-361 |
| Number of pages | 4 |
| Journal | Materials Science and Engineering B: Solid-State Materials for Advanced Technology |
| Volume | 59 |
| Issue number | 1-3 |
| DOIs | |
| State | Published - 6 May 1999 |
| Externally published | Yes |
| Event | Proceedings of the 1998 Symposium L: on Nitrides and Related Wide Band Gap Materials (E-MRS Meeting) - Strasbourg Duration: 16 Jun 1998 → 19 Jun 1998 |