Title :
A high reliability metallization system for a double metal 1.5 mu m CMOS process
Author :
Nulty, Jim ; Spadini, G. ; Pramanik, D.
Author_Institution :
VLSI Technol. Inc., San Jose, CA, USA
Abstract :
A high-reliability double-metal process is described that overcomes many of the reliability problems encountered with Al alloy films. The metallization utilizes a multilayer metal consisting of Al-1% Cu sandwiched between two TiW films. The contact resistance to both N/sup +/ and P/sup +/ are the lowest possible to both diffusions for any metallizations. As a result, contact resistance is not the limiting factor to device performance for either P-channel or N-channel devices. The current-carrying capability of both levels of metals is at least a factor of three higher than Al-Si alloys over flat areas and an order higher from via chains. The metallization is robust enough to sustain thermal and mechanical stresses without failure.<>
Keywords :
CMOS integrated circuits; aluminium alloys; contact resistance; copper alloys; integrated circuit technology; metallisation; reliability; titanium alloys; tungsten alloys; 1.5 micron; CMOS process; N-channel devices; P-channel devices; TiW-AlCu-TiW; contact resistance; current-carrying capability; double-metal process; high reliability metallization system; CMOS process; Chemistry; Circuits; Electromigration; Implants; Metallization; Nonhomogeneous media; Sputter etching; Surfaces; Very large scale integration;
Conference_Titel :
VLSI Multilevel Interconnection Conference, 1988. Proceedings., Fifth International IEEE
Conference_Location :
Santa Clara, CA, USA
DOI :
10.1109/VMIC.1988.14225
