PCM Parameters Improvement And Match Between FABs.

This project came from the request of real production, purpose is to improve semiconductor device parameters and match them between FABs. Completed NPN bipolar transistor, Lateral-PNP transistor, Pinch-Resistor, MIS-CAP, VARACTOR parameters adjustment and reached the expected value, finalized the related process conditions.Oxide was deposited on emitter poly as an excellent dielectric material to ensure the distribution profile of arsenic (the doping element), it decreased NPN Beta and increased Pinch Resistors value as well: reduced NPN Beta from 170 to 110, increased Pinch resistor of the standard device from 235 ohm to 275 ohm, increased Pinch resistor of the high voltage device from 300 ohm to 350 ohm.Lateral_PNP Beta was increased by inserting RTO before"base poly"deposition, this oxide work as wide band gap semiconductor material, it increased lateral-PNP Beta significantly, Lateral PNP beta was changed from 22 to 31.MIS-CAP value can be adjusted by varying the thickness of dielectric material (oxide), oxide growth speed was well controlled by doping concentration in silicon, found the correct doping concentration to make the MIS-CAP value at target, which is to reduce arsenic doping concentration 10% from current baseline value to make the capacitance changed from 12.5pF to 13.5pF.Varactor reached the expected value by reducing doping concentration 5% from current baseline value to make the capacitance changed from 5.64pF to 5.32pF. This is based on the theory that the Varactor can be adjusted by varying the concentration in PN light doping side.