Arthur Kenneth Hochberg

Chemical additives for improved copper chemical vapour deposition processing

Abstract Techniques for improved copper chemical vapour deposition (CVD) processing by the addition of trimethylvinylsilane (tmvs) and hexafluoroacetylacetone (Hhfac) during copper deposition from the volatile liquid precursor Cu(hfac)(tmvs) are described. The tmvs enables stable high vaporization rates of precursor by direct liquid injection and the Hhfac permits higher deposition rates of smoother copper films. The resistivity of the copper films averages approximately 1.8 μΩcm as deposited. Combined together, these results mark an important advance toward a manufacturable copper CVD process.

New OMCVD precursors for selective copper metallization

A novel OMCVD process for the highly selective deposition of pure, adherent, low resistivity copper films onto conductive substrates is described. Central to this process is a new volatile liquid copper/sup +1/ precursor, Cupra Select, designed to thermally disproportionate at low temperatures to cleanly give copper metal and volatile non-corrosive by-products. Thus, selective depositions onto metallic versus insulating dielectric substrates are achieved between 120 to 420 degrees C with growth rates in excess of 100 nm/min and grain sizes as low as 0.1 microns. In addition, a novel complementary copper etching process is discussed that is chemically compatible with the copper CVD chemistry.<<ETX>>

MOCVD of high-k dielectrics, tantalum nitride and copper from directly injected liquid precursors

Thin films of tantalum oxide and tantalum nitride for microelectronics applications can be deposited by MOCVD using direct injection of same liquid precursors of the type R-N = Ta(NEt2)3. High-k mixed-metal oxides, such as Zr–Sn–Ti–O, metal doped TaOx and zirconium silicate, can also be deposited at relatively low temperatures from liquid mixtures as single-source precursors without solvent. This solventless CVD system is considered a more cost effective and environmentally benign process than conventional liquid injection of metal–organic precursors dissolved in organic solvents. In addition, recent advances in copper CVD precursors are reviewed. Copyright

Characterization of thin copper films grown via chemical vapor deposition using liquid coinjection of trimethylvinylsilane and (hexafluoroacetylacetonate) Cu (trimethylvinylsilane)

We have developed a technique recently for copper chemical vapor deposition utilizing direct liquid coinjection of trimethylvinylsilane (TMVS) and the copper (I) precursor (hexafluoroacetylacetonate) Cu (TMVS). We present here an investigation of the properties of copper films deposited using this technique. The films were grown on Si3N4 substrates at temperatures in the range of 220–250 °C and characterized using several experimental techniques, with an emphasis placed on factors influencing copper film resistivity. The average as‐deposited film resistivity is 1.86 μΩ cm; this value is reduced to 1.82 μΩ cm when the effects of surface scattering are taken into account. The resistivity is essentially independent of film thickness for thicknesses between 0.2 and 3.5 μm, and is reduced by less than 0.05 μΩ cm by annealing at 400–600 °C in vacuum. The total impurity content of the films is approximately 100 parts per million. The film density is 97±2% of the bulk copper value. The average grain size increase...

Cyclic alkylsilanes as low-pressure chemical vapor deposition silicon dioxide precursors

Abstract Silacyclobutane and silacyclopentane were synthesized for evaluations as precursors for silicon dioxide films under low-pressure chemical vapor deposition conditions at low temperatures. Both silacyclobutane and silacyclopentane were studied in the temperature range from 300 °C to 500 °C in the presence of oxygen. Deposition rates follow an Arrhenius behavior at constant reactor pressure, and the activation energies were found to be 41.8 kJ mole−1 for silacyclobutane and 75.3 kJ mole−1 for silacyclopentane below 66.6 Pa. Silacyclobutane is susceptible to homogeneous nucleation, so obtaining optimum oxide film properties with this precursor requires lower reactor pressures as the temperature is increased. The films were analyzed by Fourier transform infrared spectroscopy for the presence of hydroxyl and hydrocarbon bands. The refractive indices were measured by ellipsometry. Carbon concentrations and Si:O ratios were estimated by Auger electron spectroscopy. Quantum mechanical semi-empirical AM1 calculations were carried out to determine the relative ring-strain energies and reactivities. These results estimate the propensity of these molecules to ring open under mild thermal conditions. The experimental results are in agreement with the calculations.

Thermal metalorganic chemical vapor deposition of Ti-Si-N films for diffusion barrier applications

Structurally disordered refractory ternary films such as titanium silicon nitride (Ti-Si-N) have potential as advanced diffusion barriers in future ULSI metallization schemes. Here the authors present results on purely thermal metalorganic chemical vapor deposition (CVD) of Ti-Si-N. At temperatures between 300 and 450 C, tetrakis(diethylamido)titanium (TDEAT), silane, and ammonia react to grow Ti-Si-N films with Si contents of 0--20 at.%. Typical impurity contents are 5--10 at.%H and 0.5 to 1.5 at.% C, with no O or other impurities detected in the bulk of the film. Although the film resistivity increases with increasing Si content, it remains below 1,000 {micro}{Omega}-cm for films with less than 5 at.% Si. These films are promising candidates for advanced diffusion barriers.

The LPCVD of Silicon Nitride Films from Alkylazidosilanes

The series of azidosilanes, SiEt n (N 3 ) 4-n where n = 1,2,3 and Si(t-butyl)(N 3 ) 3 were evaluated for the LPCVD of silicon nitride thin films. Both SiEt(N 3 ) 3 and Si(t-butyl)(N 3 ) 3 gave deposition rates of approximately 100 A/min at temperatures of 450–500°C but films appear to be porous and air sensitive. Film properties improved as deposition temperatures were increased to 600°C. The polyazides must be handled with extreme caution. An unexplained detonation of one sample of SiEt(N 3 ) 3 occurred during the course of this study.