Tadashi Onishi

Advanced EB-cure process and equipment for low-k dielectric

Recently IC makers have requested single wafer processes because the number of wafers in 1 lot is small and the size of the wafers are larger. Usually spin on low-k material is used by the furnace (FNC) for long time thermal cure process. A new electron beam (EB) cure equipment and process are developed to improve the mechanical strength of low-k dielectric, to reduce the time of cure process and to reduce thermal budget. By EB curing, JSR LKD (low k dielectric) material (k = 2.9) becomes 1.6 times stronger than conventional film. EB cure also shows considerable merit over FNC in cure time and power consumption for small batch size processing. For single wafer processing, the cure time is reduced from 30 minutes to 2 minutes. The power consumption is less than half of the FNC case for 25 wafer processing. Electric charge up damage is measured and proved not much of a drawback for devices.