Enhancement-mode AlGaN/GaN high electronic mobility transistors with thin barrier

An enhancement-mode （E-mode） A1GaN/GaN high electron mobility transistor （HEMTs） was fabricated with 15-nm A1GaN barrier layer. E-mode operation was achieved by using fluorine plasma treatment and post-gate rapid thermal annealing. The thin barrier depletion-HEMTs with a threshold voltage typically around -1.7 V, which is higher than that of the 22-nm barrier depletion-mode HEMTs （-3.5 V）. Therefore, the thin barrier is emerging as an excellent candidate to realize the enhancement-mode operation. With 0.6-tim gate length, the devices treated by fluorine plasma for 150-W RF power at 150 s exhibited a threshold voltage of 1.3 V. The maximum drain current and maximum transconductance are 300 mA/mm, and 177 mS/ram, respectively. Compared with the 22-nm barrier E-mode devices, VT of the thin barrier HEMTs is much more stable under the gate step-stress,

薄隔层层间窜流原因分析及技术对策

薄隔层地层固井中射孔和压裂对水泥环造成的破坏易引起环空窜流,针对这一问题,开展环空窜流主因分析,通过提高顶替效率、平衡压力、短候凝固井技术、使用管外封隔器、改善水泥石抗冲击能力等针对性技术措施,成功解决了油水薄隔层射孔投产后环空窜流的问题。对解决薄隔层地层固井质量低、易发生水窜的难题具有良好的指导意义。