Comparison of the Ta/sub 2/N--Cr--Au and Ta/sub 2/N--Cr--Pd--Au hybrid metallization systems--dc electrical properties, resistor aging, corrosion resistance, and chromium layer depletion studies

Technical Report · Mon May 01 04:00:00 EDT 1978

OSTI ID:6486521

Hampy, R E; Villanueva, J; Ganyard, F P

In an attempt to overcome some of the deficiencies of Ta/sub 2/N--Cr--Au thin films (400, 300, and 60,000 A, respectively), an alternate metallization incorporating palladium, i.e., Ta/sub 2/N--Cr--Pd--Au (400, 300, 500, and 60,000 A, respectively), was evaluated on a comparative basis with the standard system. Comparable results were obtained in tantalum resistor aging studies and temperature coefficient of resistance (TCR). The conductor resistance was slightly higher, and the contact resistance to the tantalum nitride was about 50% higher for the alternate system. The addition of 500 A of palladium slowed down the chromium diffusion during the two hour, 300/sup 0/C resistor stabilization step, although after six hours at 300/sup 0/C, the chromium diffusion was greater. It was still necessary to etch the chromium oxide to obtain good lead bonds and, furthermore, the alternate system was more vulnerable to chromium layer attack by the etchant than the standard system. Later studies showed that with 2000 A of palladium, the chromium diffusion was slowed sufficiently that the oxide etch step could be eliminated and good lead bond strengths attained. The iodine sensitivity was effectively eliminated by the addition of 500 A or 2000 A of palladium and the resistance to HCl vapor was improved. If the processing times at high temperatures can be kept short and the chromium oxide etch step eliminated, the alternate metallization should be an improvement over the Ta/sub 2/N--Cr--Au system.

• Research Organization: Sandia Labs., Albuquerque, NM (USA)
• DOE Contract Number: EY-76-C-04-0789
• OSTI ID: 6486521
• Report Number(s): SAND-78-0604
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
AGING
CHROMIUM
DIFFUSION
DIMENSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
ETCHING
FABRICATION
FILMS
GOLD
HIGH TEMPERATURE
LAYERS
METALS
NITRIDES
NITROGEN COMPOUNDS
PALLADIUM
PERFORMANCE
PHYSICAL PROPERTIES
PLATINUM METALS
PNICTIDES
SURFACE FINISHING
TANTALUM COMPOUNDS
TANTALUM NITRIDES
THICKNESS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS