An Rfid Products For Esd, Eeprom Problem Analysis And Resolution,

ELECTRO STATIC DISCHARGE is not a fresh thing, but it make great destroy, especially RFID card product. During making module and card process, it will generate strong electrostatic, and also different factory has different condition so ESD protection is very important. This thesis analysis and solve the ESD problem of RFID product of my company to lower the failure rate during process and application, enhance product performance, and raise the ability of competence.Through measure/compare, analysis, experiment and verification, I get a great deal of data to show the reason why the yield of product is low. I confirm that the circuit does not work and low performance because all kinds of ESD mode ability are too low.At the same time, the root cause of WAFER test yield low is that the over etching of poly 1 results in gate oxide damage which makes the select transistor of EEPROM have a leakage. The leakage makes the select transistor keeps in "open" and loses its function. So, if the bit cell logic is "1", the cell is "open" and the bit line will have a significant leakage which results in the other bits in the same bit line are all " 1" when they are selected for being read. In this case the EEPROM failure in chess mode is happened easilyThrough improve the chip design:add ESD protection circuit around the failure device; adjust wafer process:add PWELL implant in ESD protection device to protect the failure device to solve the ESD problem.By adjusting the etch process to increase the poly 1 CD and adding the RTP for gate oxide after polyl plasma etching to dispel the damage. We have solved the EEPROM checkerboard failure.