Study Of Micromachining On Silion Using Short And Ultrashort Laser Pulses

At present laser processing technology has been applied to many aspects of production and life.The short pluse laser machining which has a very good prospect in the semiconductor industry has a lot of merits on micromachining such as relatively narrow pluse width, high average power, high repetition rate, high processing efficiency, and it can be focused into a smaller spot to achieve precision machining.The novel micromachining method, ultrashort pluse laser machining also has a lot of significant advantages, such as high quality of materials removal, high aspect ratio in micrometer level and so on. The method is expected to overcome the disadvantages in other micromachining technologies. They both have their own characteristics and advantages in processing.In this dissertation, a series of ablation experiments on Si surface by 355nm, <40ns, 20KHz nanosecond pluse laser and 775nm, 150fs, 1KHz femtosecond laser are carried out. The interactional mechanism between the semiconductor and nanosecond pluse lase & femtosecond pulse laser was analyzed, which supports the experiment of microstucture machining on Si surface. The morphological characteristics of machined structures are tested bySEM, FIB and optic microscope. In this paper, it is discussed that various influences on micro machined structures by changing laser parameters, including laser fluence, laser pulse number, velocity of the motion stages, during the structures micromachining.The different effects of micromachining by nanosecond pluse lase and femtosecond pulse laser were analyzed, and their respective characteristics in microprocessing are obvious.