Design And Fabrication Of High Luminous Efficiency GaN-based LED Chip

Light emitting diode（LED） is replacing the traditional illumination source, because oftheir advantages, such as long lifetime, low energy consumption, high light efficiency, etc.However，it is difficult for LED lighting to enter the ordinary family, because of smallluminous and high price. This hindered the popularity of the green light source.Chip technology upgrading and lower prices are the keys to reduce the cost of LED lighting,which promote the study of high luminous efficiency LED chips. We make an explorativeresearch on new structures of the high light extraction efficiency LED chip using severalmainstream manufacture techniques of LED chip.Based on optical transfer matrix theory, a distributed Bragg reflector （DBR） consistingof SiO₂and Ti₃O₅is designed as the current barrier layer for high brightness LED chips,and a trench structure is etched by inductively coupled plasma （ICP） technique on thecurrent barrier. The problems that current spreading restricts the improvement of the LEDdevices efficiency and that the metal electrodes reduce optical efficiency can be solved by thisway. The experiment results indicates that the brightness of the LED chip with this structurecan be increased by5%, while the chip voltage is essentially unchanged, which shows that thenew structure can greatly ameliorate current spreading and increase the extraction efficiencyof LED chip.In order to solve the problem of the current crowding of high power LED chip, we focuson the new structures, different electrode shapes and manufacture processof the high-voltage LED chips. A light-transferring pole structure is designed in high-voltageLED chip, and the ICP etching program is improved to achieve the chip shaping effects. Theexperiment results shows that the brightness of the high-voltage LED chip with light-transferring pole can be increased by6%, and the manufacture process is stable, which isconducive to mass production.