A novel CVD copper process is described using
two new copper CVD precursors, KI3 and KI5, for
the fabrication of IC or TSV (Through Silicon Via)
copper interconnects. The highly conformal CVD
copper can provide seed layers for subsequent
copper electroplating or can be used to directly
fabricate the interconnect in one step. These
new precursors are thermally stable yet chemically
reactive under CVD conditions, growing copper
films of exceptionally high purity at high growth
rates. Their thermal stability can allow for
elevated evaporation temperatures to generate
the high precursor vapor pressures needed for
deep penetration into high aspect ratio TSV vias.
Using formic acid vapor as a reducing gas with
KI5, copper films of > 99.99 atomic % purity
were grown at 250°C on titanium nitride at a
growth rate of > 1500 Å/min. Using
tantalum
nitride coated TSV type wafers, ~ 1700 Å of
highly conformal copper was grown at 225°C into
32 μm × 5 μm trenches with good adhesion. With
ruthenium barriers we were able to grow copper
at 125°C at a rate of 20 Å/min to give a
continuous ~ 300 Å copper film. In this respect,
rapid low temperature CVD copper growth offers
an alternative to the long cycle times associated
with copper ALD which can contribute to copper
agglomeration occurring.
© 2008 Elsevier B.V.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa.de:bsz:ch1-200801346 |
| Date | 02 October 2008 |
| Creators | Norman, John A. T., Perez, Melanie, Schulz, Stefan E., Waechtler, Thomas |
| Contributors | TU Chemnitz, Fakultät für Elektrotechnik und Informationstechnik, Air Products and Chemicals, Inc.,, Elsevier B.V., |
| Publisher | Universitätsbibliothek Chemnitz |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | doc-type:article |
| Format | application/pdf, text/plain, application/zip |
| Source | Microelectronic Engineering 85 (2008), 2159-2163 |
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