Semiconductor manufacturing industries, covering ICs (Integrated Circuits), discrete components (MOSFET, transistor, IGBT, etc ), MEMS (Micro-Electrical Motor systems), SAW (Surface Acoustic Wave) components, LED (backlight for display, lighting), and so on, involves large amounts of electrostatic impacts. From front-end wafer fabrication to back-end assembly, electrostatics could impact semiconductor devices on Production Yields on electrical failures and Reliabilities.
In front-end wafer fabrications, electrostatics commonly impact semiconductors in forms of below situations:
a. Plasma effects stressed on semiconductor dielectrics in PECVD, PVD, Ion Implantations, Dry-etching, plasma ashing, etc.
b. Electrostatic charging and accumulation on semiconductor dielectrics in photo-resist coater (spin type), EUV lithography, develop and wet etching, stripper.
c. Electrostatics would also impacts severely on photomasks (or called reticles) by chrome pattern CD (Critical Dimension) failures which would lead to costly loss to wafer fabrication yields.
In back-end assembly and testing production lines, electrostatics often impact production yield loss in below situations:
a. Electrostatics charging and highly residuals on wafers in tape mounting, tape peeling of wafer sawing and wafer back grinding processes.
b. Electrostatics would induce semiconductor failures in high pressure HPW or DIW rinsing in wafer sawing and wafer taping/peeling of wafer back grinding processes.
c. Electrostatics could impact semiconductors by ESD in die attachment, wire bonding and various electrical testing processes.