ChemInform Abstract: Aluminum Metallization Using a Combination of Chemical Vapor Deposition and Sputtering.

Abstract

Aluminum Metallization Using a Combination of Chemical Vapor Deposition and Sputtering.-A combination process meeting the requirements for ULSI (ultralarge scale integration) interconnections and being promising for the manufacturing of subhalf micron multilevel interconnections for ULSI comprises hole filling by CVD of Al from Me2AlH onto TiN followed by film thickening by Al alloy sputtering. Via holes with a diameter of 0. 3 µm and an aspect ratio of 2.7 are successfully filled at 130 . degree.C. Contact resistivities of p-and n-type Si of 1.0 · 10-7 and 2.9 · 10-8 Ω cm2, resp., and for via holes of 1.6 . times. 10-9 Ω cm2 are obtained by this process. -(SUGAI, K.; KISHIDA, S.; SHINZAWA, T.; OKABAYASHI, H.; YAKO, T.; KADOKURA, H.; ISEMURA, M.; KOBAYASHI, T.; HOSOKAWA, N.; J.

Morphology and Hole Filling Properties of Chemically Vapor Deposited Aluminum Films Prepared from Dimethylethylamine Alane

“…Thus, an increment in the density of nuclei is believed to be a key factor for the resolution of the problem of rough-surfaced CVD Al films. 5,[8][9][10]17 DMEAA is known to deposit Al films readily on most metallic surfaces, but not on dielectrics such as SiO 2 and Si 3 N 4 . Interestingly, it was also reported that Al films could be formed on various metal surfaces coated with native metal oxide layers.…”

“…There are various source chemicals for CVD aluminum, such as trimethylaluminum, 1 triisobutylaluminum (TIBA), [2][3][4][5][6] dimethylaluminum hydride (DMAH), [7][8][9][10] and amine-alane adducts such as trimethylamine alane, 11 triethylamine alane, 12 and dimethylethylamine alane. [13][14][15][16][17] Among these precursors, dimethylethylamine alane (DMEAA) is considered to be the most promising precursor for Al CVD due to the absence of carbon contamination in its deposits, its high vapor pressure, and low deposition temperature; it also has the additional advantage of being liquid.…”

“…The rough topography can cause not only voids in the deposits leading to a reliability problem but also difficulties in integration of the CVD Al with photolithography and etch. 5,[8][9][10]12,16,17 This rough surface morphology is known to be caused by the slower nucleation of CVD Al compared with the subsequent film growth. To enhance the nucleation density and improve the surface morphology of Al films, a "ramping down" process and chemical pretreatment of the substrate surface has been suggested.…”

“…To enhance the nucleation density and improve the surface morphology of Al films, a "ramping down" process and chemical pretreatment of the substrate surface has been suggested. 6,8,18 For example, in situ chemical pretreatment of the substrate with tetrakis(dimethylamino)titanium (TDMAT) was found to be effective at increasing nucleation, which results in a decrease of the surface roughness of CVD Al films. 8 In spite of the common use of plasma pretreatment to provide a clean surface for the CVD process in IC fabrication, 19 only a few studies have reported the effects of plasma pretreatment on film growth of CVD Al films.…”

“…6,8,18 For example, in situ chemical pretreatment of the substrate with tetrakis(dimethylamino)titanium (TDMAT) was found to be effective at increasing nucleation, which results in a decrease of the surface roughness of CVD Al films. 8 In spite of the common use of plasma pretreatment to provide a clean surface for the CVD process in IC fabrication, 19 only a few studies have reported the effects of plasma pretreatment on film growth of CVD Al films. 17 Therefore, in this work, the effects of in situ plasma pretreatment of air-exposed TiN on the surface morphology and the gap-filling properties of CVD Al were systematically investigated under various pretreatment conditions at a range of temperatures.…”