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Study of SiH4-based PECVD Low-k Carbon-doped Silicon Oxide Hongning Yang, Douglas J. Tweet, Lisa H. Stecker, Wei Pan, David R. Evans, and S.-T. Hsu Sharp Laboratories of America, Inc., 5700 NW Pacific Rim Blvd., Camas, WA 98607 ABSTRACT In previous studies, low-k carbon-doped silicon oxide (SiOC) films were deposited using organosilicon precursor: (CH3)xSiH4-x. In this paper, we present the properties of PECVD low-k SiOC films produced by using conventional SiH4 based gas precursors. The SiH4 based SiOC films have similar gross physical and electrical characteristics to those of (CH3)xSiH4-x based SiOC. Since the precursors are inexpensive, commercially available and convenient to operate for existing tools, the process should not require additional cost as compared with that of PECVD silicon dioxide. We demonstrate the feasibility of integrating Cu with SiOC on damascene interconnection. The evaluation on electrical performance of the Cu/ SiOC based damascene structure will be discussed. INTRODUCTION Recently, carbon-doped silicon oxide (SiOC) has been emerging as one of the best low-k candidates for delivering the required performance of interconnect dielectric (ILD) in future ULSI devices [1]. SiOC has a dielectric constant ranging between 2.5 and 3.2 with sufficient mechanical strength and adhesion properties. SiOC preserves some beneficial characteristics of SiO2, so that the integration of SiOC with Cu can utilize those traditional well-developed processes and technology, such as PECVD, etch and CMP. Clearly, the replacement of SiO2 by SiOC shows advantages in a simple and low cost transition from SiO2 to low-k ILD. The reduction of dielectric constant can be achieved by doping methyl (-CH3) group into SiO2 network to form SiOC, where some of Si-O bonds are replaced by Si-CH3 bonds. Since the termination of O-Si-O cross-linking by -CH3 creates volume, the higher carbon concentration in SiOC can thus lead to a lower dielectric constant. In previous studies, PECVD SiOC films were deposited using organosilicon precursor: (CH3)xSiH4-x [1 - 4], such as methylsilane (x = 1) [5], trimethylsilane (x = 3) [1 – 4] and tetramethylsilane (x = 4). In this paper, we show that SiOC films can be produced by using conventional SiH4 based gas precursors, which are the mixture of SiH4 and hydrocarbon gas. The SiH4 based SiOC films have similar gross physical and electrical characteristics to those of (CH3)xSiH4-x based SiOC. The dielectric constant ranges from 2.8 to 3.2 with density from 1.4 to 1.7 g/cm3 correspondingly. Leakage current is measured in an order of 10-9 A/cm2 at a field of 106 V/cm. The films are stable against thermal anneal at > 400 ºC. Post anneal for as-deposited film may not be necessary if appropriate process conditions are chosen. We have also demonstrated the feasibility for the integration of Cu and SiOC on damascene interconnection. Since the SiH4 based precursors are relatively inexpensive, commercially available and convenient to operate for existing tools, the process may not require additional cost a