Ni based OHMIC contact on p-type GaN
| dc.date.accessioned | 2016-11-01T03:16:31Z | |
| dc.date.available | 2016-11-01T03:16:31Z | |
| dc.date.issued | 2005-10 | |
| dc.description.abstract | A new metallization scheme of Nil Ag on p-type GaN was studied to obtain reliable ohmic contact. Silver (Ag) was selected as capping layer due to its characteristics as the best metallic reflectors at visible wavelengths as an approach to employ the flip-chip configuration. The contacts were first fabricated using the conventional photolithography method. Then, the Ni/Ag metals were coated onto the p-GaN wafer through D.C. Sputter equipment. Circular TLM structures were fabricated to extract the specific contact resistivity of the contacts. The contacts were then annealed in rapid thermal process (RTP) machine. In order to acquire lower resistance metal semiconductor interface; different Nickel thickness, annealing duration (30 seconds, 1 minute and 2 minutes), as well as 2 different annealing ambient were applied on this contacts. The contacts exhibited ohmic behavior at the annealing temperature of 600°C and 700°C. The contact which produces the lowest specific contact resistivity is the sample that underwent annealing at 600°C in vacuum ambient for 1 minute (Pc = 3.14 X 10.2 Ocm2 ). In terms of surface morphology, annealing in vacuum ambient has definitely produced contacts which resulted in a lot lower surface roughness compared to those contacts annealed in nitrogen ambient. The characterization of surface morphology was conducted using the scanning electron microscopy (SEM) and the atomic force microscopy (AFM). X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) were utilized to determine the microstructural condition of the contacts. The electrical properties of the contacts were carried out using the current-voltage (I-V) system. Fabrication of the Ni/Ag contacts on p-type GaN were successfully fabricated and characterized. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/2939 | |
| dc.subject | A new metallization scheme of Nil Ag on p-type GaN | en_US |
| dc.subject | was studied to obtain reliable ohmic contact | en_US |
| dc.title | Ni based OHMIC contact on p-type GaN | en_US |
| dc.type | Thesis | en_US |
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