The photoluminescence (PL) properties of Mn-doped zinc silicates were studied by combinatorial synthesis and characterization technique associated with various process parameters. The material libraries were prepared with composition spreading in Zn and Mn concentration. The PL emission was green or orange, and depended strongly on the stoichiometry of the zinc silicates and the annealing temperature. The orange emission was observed in Mn-doped zinc silicates annealed at 800°C, which attributed to the increase of crystal field in a highly non-stoichiometric α-Zn2SiO phase ((Zn+Mn)/Si <1).

Hafnium silicates (HfO2:SiO2, HSO) have recently attracted much interest in the fields of fundamental science and technology because they have high dielectric constant and low leakage current. The structure and properties of HSO gate oxides were studied using a combinatorial continuous-compositional-spread method. HSO material libraries were synthesized on a 4-inch wafer at room temperature and at 200°C using a custom-built radio-frequency (RF) sputtering system. The electrical properties of HSO material libraries were measured using metal-oxide-semiconductor structure. X-ray diffraction (XRD) was utilized to characterize the structure and compositions of HSO material libraries. The effects of sputtering conditions on the properties of the HSO gate oxides were investigated. The dielectrics constants (εr) of HSO material libraries treated with rapid thermal annealing (600°C/1min/N2) were in the range 5∼23, as determined by C-V measurement, and the dielectric constant was observed to increase with HfO2 content. The I-V relations of the HSO material libraries indicate that the leakage current decreases as the amount of Si in the HSO films increases. The structural characteristics of HSO films with RTA treatment (1000°C/10sec/N2) varied from the amorphous to the crystalline state (tetragonal and monoclinic phase), according to the composition of material libraries. The correlation among the electrical properties, the composition and the crystal structure of the HSO films is discussed.

We have investigated TiN/TiSi2 films as diffusion barriers between copper and silicon. The TiN/TiSi2 films were formed by annealing Ti/Si via rapid thermal process at a temperature of 850'C for 30 seconds in N2 ambient. The contact resistance and leakage current of the Cu/TiN/TiSi 2/n+-p Si contact system were measured after sintering at 350-600°C for 30 minutes in an N2 ambient. We found an abrupt increase of contact resistance occurred at a sintering temperature of 600°C. From the leakage current of n+-p diode, we observed that the thermally stable temperature was about 475ycC. Meanwhile, XTEM photographs showed small Cu3Si crystallites with size of about 0.25 μm precipitated in the n+Si substrate at a sintering temperature 500°C. The formation of Cu3Si increases the occupied volume, generates the gap between TiSi2 and n+Si, and gradually increases the specific contact resistance. SIMS profiles also showed that a certain amount of Cu atoms diffused into the n+-p Si junction and that Si atoms existed in the Cu film. The Cu3Si formation across the n+-p junction can explain the abrupt increase in the leakage current measurement at 500°C. So the failure mechanisms for contact resistance and leakage current are different.