Deposition of thin metal films in via holes of LSI by using the IBE method

The characteristics of an ablation plasma generated by using an intense, pulsed ion beam were studied experimentally by using high-speed photography and calorimetry. From the high-speed photographs, it is found that the ablation plasma were found to expand toward the substrate, and it is kept for about 20 μs after the start of the beam irradiation. The calorimetry diagnostic results should that the thermal energy carried by the ablation plasma instantly, a increased the substrate surface temperature to over 900 K. After that, thermal conduction in the substrate dominated and the temperature dropped at a rate of 10⁸ K/s. Using the high-density ablation plasmas produced by pulsed ion beam interaction with solid targets, we successfully embedded tungsten thin films in via holes with an aspect ratio of 4.3, not only in the bottom of the silicon, but also in the side walls.