In this study, a low-temperature annealed ohmic contact process was proposed on AlGaN/GaN heterostructure field effect transistors （HFETs） with the assistance of inductively coupled plasma （ICP） surface treatment....In this study, a low-temperature annealed ohmic contact process was proposed on AlGaN/GaN heterostructure field effect transistors （HFETs） with the assistance of inductively coupled plasma （ICP） surface treatment. The effect of ICP treatment process on the 2DEG channel as well as the formation mechanism of the low annealing temperature ohmic contact was investigated. An appropriate residual AlGaN thickness and a plasma-induced damage are considered to contribute to the low-temperature annealed ohmic contact. By using a single Al layer to replace the conventional Ti/Al stacks, ohmic contact with a contact resistance of 0.35 Ω.mm was obtained when annealed at 575 ℃ for 3 min. Good ohmic contact was also obtained by annealing at 500 ℃ for 20 rain.展开更多
The manufacturing of bioimplants not only involves selecting proper biomaterials with satisfactory bulk physicochemical properties, but also requires special treatments on surface chemistry or topography to direct a d...The manufacturing of bioimplants not only involves selecting proper biomaterials with satisfactory bulk physicochemical properties, but also requires special treatments on surface chemistry or topography to direct a desired host response. The lifespan of a bioimplant is also critically restricted by its surface properties. Therefore, developing proper surface treatment technologies has become one of the research focuses in biomedical engineering. This paper covers the recent progress of surface treatment of bioimplants from the aspects of coating and topography modification. Pros and cons of various tech- nologies are discussed with the aim of providing the most suitable method to be applied for different biomedical products. Relevant techniques to evaluate wear, corrosion and other surface properties are also reviewed.展开更多
文摘In this study, a low-temperature annealed ohmic contact process was proposed on AlGaN/GaN heterostructure field effect transistors （HFETs） with the assistance of inductively coupled plasma （ICP） surface treatment. The effect of ICP treatment process on the 2DEG channel as well as the formation mechanism of the low annealing temperature ohmic contact was investigated. An appropriate residual AlGaN thickness and a plasma-induced damage are considered to contribute to the low-temperature annealed ohmic contact. By using a single Al layer to replace the conventional Ti/Al stacks, ohmic contact with a contact resistance of 0.35 Ω.mm was obtained when annealed at 575 ℃ for 3 min. Good ohmic contact was also obtained by annealing at 500 ℃ for 20 rain.
文摘The manufacturing of bioimplants not only involves selecting proper biomaterials with satisfactory bulk physicochemical properties, but also requires special treatments on surface chemistry or topography to direct a desired host response. The lifespan of a bioimplant is also critically restricted by its surface properties. Therefore, developing proper surface treatment technologies has become one of the research focuses in biomedical engineering. This paper covers the recent progress of surface treatment of bioimplants from the aspects of coating and topography modification. Pros and cons of various tech- nologies are discussed with the aim of providing the most suitable method to be applied for different biomedical products. Relevant techniques to evaluate wear, corrosion and other surface properties are also reviewed.
