Title :
Influence of back-end thermal processing on polysilicon-monosilicon contact resistance due to dopant deactivation
Author :
Perera, Asanga H. ; Taylor, William J. ; Orlowski, Marius
Author_Institution :
Adv. Products Dev. & Res. Lab., Motorola Inc., Austin, TX, USA
Abstract :
The effect of post-planarization rapid thermal anneal (RTA) steps on polysilicon-monosilicon contact resistance is critically dependent on the thermal requirements of the specific planarization technique used. While these RTA steps were found to increase Rc,polyn+/ for chemical mechanical polishing (CMP) type low or zero thermal budget back-end processes, they decreased Rc,polyn+/ when furnace glass reflow anneals were used. For a CMP back-end process when a high temperature (⩾1000°C) RTA is used to form the shallow n+ emitter junction, all subsequent anneals need to be carefully optimized to avoid drastic increases in Rc,polyn+/-for a 1065°C emitter RTA and 850°C RTA process, a 700°C RTA caused a 62% increase for a 30 sec anneal and a 125% increase for a 300 sec anneal
Keywords :
contact resistance; 30 to 300 s; 700 to 1065 C; CMP back-end process; Si; back-end thermal processing; chemical mechanical polishing; dopant deactivation; furnace glass reflow anneals; planarization technique; polysilicon-monosilicon contact resistance; post-planarization RTA; rapid thermal anneal; shallow n+ emitter junction; BiCMOS integrated circuits; Contact resistance; Fabrication; Furnaces; Glass; Planarization; Rapid thermal annealing; Rapid thermal processing; Thermal conductivity; Thermal resistance;
Conference_Titel :
Bipolar/BiCMOS Circuits and Technology Meeting,1994., Proceedings of the 1994
Conference_Location :
Minneapolis, MN
Print_ISBN :
0-7803-1316-X
DOI :
10.1109/BIPOL.1994.587904
