Gerald Lynn Leake2436 Greenock Buena Vista Rd, Mckeesport, PA 15135

2008012, May 29, 2008

Nov 27, 2006

11/563476

Min Chul Sun - Gyeonggi-do, KR
Jong Ho Yang - Fishkill NY, US
Young Gun Ko - Fishkill NY, US
Ja Hum Ku - Gyeonggi-do, KR
Jae Eon Park - Gyeonggi-do, KR
Jeong Hwan Yang - Gyeonggi-do, KR
Christopher Vincent Baiocco - Newburgh NY, US
Gerald Leake - McKeesport PA, US

H01L 21/8238
H01L 21/336

438230, 438303, 257E21409, 257E21632

Methods of forming field effect transistors include methods of forming PMOS and NMOS transistors by forming first and second gate electrodes on a substrate and then forming an electrically insulating layer having etch-enhancing impurities therein, on the first and second gate electrodes. The electrically insulating layer may be formed as a boron-doped silicon nitride layer or an electrically insulating layer that is doped with germanium and/or fluorine. The electrically insulating layer is etched-back to define first sidewall spacers on the first gate electrode and second sidewall spacers on the second gate electrode. P-type source and drain region dopants are then implanted into the semiconductor substrate, using the first sidewall spacers as a first implant mask. The second sidewall spacers on the second gate electrode are then etched back to reduce their lateral dimensions. N-type source and drain region dopants are then implanted into the semiconductor substrate, using the second sidewall spacers with reduced lateral dimensions as a second implant mask.