The tensile bond strength in the groups treated with the ultrasonic scaler exhibited approximately twice the strength observed in groups treated with laser irradiation alone.

The bond strengths in treated with air-powder polished group and phosphoric acid etched group were significantly higher than that of the group in laser irradiation alone.

No abstract

IGBT terminal capacitances play an important role in IGBT switching transients. The terminal capacitance modelling, particularly Miller capacitance modelling, is a difficult task due to their operating-point-dependent characteristics. Previously, for the planar gate IGBT, the Miller capacitance's voltage dependency is modelled by considering the depletion region growth pattern. For modern trench gate design, however, there is no similar dynamic process available. Also, its current dependency needs to be taken account of. This paper presents an improved IGBT physics-based model with proper terminal capacitance correction. By comparison of experimental and simulation results, the proposed model works brilliantly for different types of IGBTs (including the state-of-art trench-gate field-stop type) over a wide range of operating conditions.

Low kinetic energy particle bombardment of a growing film surface has been employed to grow high-quality copper thin films on silicon and SiO2 with ideal metal/substrate interface characteristics. It is shown that the energy of Ar ions concurrently bombarding a growing film surface determines the crystal structure of the film. Under relatively low-energy ion bombardment conditions, (100)-or (lll)-oriented Cu films are grown epitaxially on (100) Si or (111) Si surfaces, respectively. On the other hand, completely (lll)-oriented films are obtained either on (100) Si, (111) Si, or SiO2 surfaces when large ion bombardment energies are employed. It has been found that (111)-oriented films thus created on SiO2 are metastable and easily transform by thermal annealing into completely (100)-o~iented films with large grains of about 100 ~m. This unique transformation phenomenon has been successfully applied to the formation of almost single-crystal (100)oriented Cu islands on SIO2. In situ substrate surface cleaning by extremely low energy Ar ion bombardment has enabled the formation of ideal metal/silicon contacts without any postmetallization alloying heat cycles. Excellent adhesion of Cu thin films on SiO2 has also been demonstrated by the employment of the in situ substrate surface cleaning.