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Amorphous SiC (a-SiC) films are the most promising dielectric diffusion barriers to replace silicon nitride in Cu-interconnect technology. However, reclaim of wafers with a-SiC films is a challenge issue for mass production. In this paper, a novel wafer reclaim method is proposed. It is observed that a-SiC can be oxidized to Si[O.sub.2] in both dry [O.sub.2] and steam ambients at temperatures as low as 550 [degrees]C. The oxidation mechanism can be described by the Deal-Grove model that is traditionally used to describe oxidation of Si. Experiments prove that the oxidation process is clean and uniform. It is also observed that carbon doped oxide (CDO) films can be oxidized easily, too. Therefore, oxidation followed by HF etching could be a universal process to reclaim wafers deposited with a-SiC or CDO films. Since the oxidation rate of Si substrates at medium temperatures is much lower than that of a-SiC and CDO films, the oxidation process is virtually self-limiting. Compared with a traditional reclaim method based on wafer polishing, this universal oxidation-etching method exhibits great benefits in terms of low cost, high throughput, and the ability to perform nearly unlimited numbers of reclaim cycles. Index Terms--Amorphous silicon carbide, low dielectric constant, wafer reclaim.

Sacrificial layer (SACL) coating had been proposed to protect the sealing layer of underlying copper lines during trench etching as via-first scheme is employed for dual-damascene patterning. Because the coated SACL thickness depends on via size and via density, the process window is hard to identify. In this paper, the criteria for a successful SACL process are derived. A four-step procedure for SACL process developing is also proposed. It is suggested that shallow trench depth and medium etch rate selectivity between inter-metal-dielectric and SACL material are preferred. The SACL thickness in via can be adjusted by adjusting the overetching percentage at the SACL breakthrough step so that the criteria are satisfied. The validity of the proposed criteria is proved by the very high yield of via chains with via size ranging from 0.27 to 0.16[micro]m. It is concluded that the SACL process can be robust and can be employed to reduce the thickness of the capping layer effectively even beyond the 0.13-[micro]m technology node. Index Terms--Copper, dual-damascene, interconnections.

Electrical instabilities of a-SiC:H film during electric-field stress are examined. A dialectric polarization model is proposed to explain high electric-field instability.

Numerical simulations are conducted to investigate the effect of contact interface recession on the external resistance of self-aligned silicided (salicide) source/drain structures. It is shown that the silicidation mechanismcauses a rise in resistance that may be in the order of several hundred ohms-micrometers. The simulated results are then compared to reported measurements of external resistance for which a 20% error is found.

Experimental results of a study investigating the influence of fluorine contained in ions implanted into platinum silicide structures are reported. Both implantation-through-metaland implantation-through-silicide cases are analyzed to analyze the high-temperature stability obtained through flourine inclusion. A fluorine-buffer model is developed to account for the improvement and a hypothesis concerning the Si-F layer's role is proposed. Fabricated Schottky junctions with and without fluorination are also evaluated.

The fluorine-buffer model facilitates the introduction of fluorine at the silicide/silicon interface to enhance the thermal stability of the interfacial system. Fluorinated silicide film grains grow more rapidly than unfluorinated grains. The buffer model is superior to the grain growth retardation model that restricts the fluorine ions to the silicide layer.

Metal ions, which drifted into nano-porous CDA are investigated. It is observed that both the AI and Cu ions can be driven into porous CDO film easily by applying electric field or thermal treatment. The investigations discovered that the lacking formation of A1(sub 2)O(sub 3) interfacial layer caused A1 ions to migrate into CDO film and that the CDO porous structure would enhance metal ions movement in it.