Effect of hydrogen dilution on the deposition of carbon-rich a-SiC:H films by the electron cyclotron resonance method

The deposition of hydrogenated amorphous silicon carbide (a-SiC:H) films from a mixture of silane, acetylene and hydrogen gas using the electron cyclotron resonance chemical vapour deposition (ECR-CVD) process is reported. The variation in the deposition and film characteristics such as the deposition rate, optical band gap and IR absorption as a function of the hydrogen dilution is investigated. The deposition rate increases to a maximum value of about 250 Å min-1 at a hydrogen dilution ratio of about 20 (hydrogen flow (sccm)/acetylene + silane flow (sccm)) and decreases in response to a further increase in the hydrogen dilution. There is no strong dependence of the optical band gap on the hydrogen dilution within the dilution range investigated (10-60) and the optical band gap calculated from the E04 method varied marginally from about 2.85 to 3.17 eV. The room temperature photoluminescence (PL) peak energy and intensity showed a prominent shift to a maximum value of about 2.17 eV corresponding to maximum PL intensity at a moderate hydrogen dilution of about 30. The PL intensity showed a strong dependence on the hydrogen dilution variation.

Manufacturing clarity

A framework has been developed for the UK economy that categorizes companies who provides a more defined perspective on the structure of the economy in order to help decision makers, government and industry to achieve sustained economic growth. The Institute for Manufacturing (IfM) has established a broader definition of manufacturing that equates manufacturing to the full cycle of activities from research and development, through design, production, logistics and services, to end of life management, within an economic and social context. This approach recognizes that manufacturing firms turn ideas into products and services and that they are inventors, innovators, global supply chain managers and service providers. It is hoped that this categorization provides policy-makers with a clear frame of reference for discussing measures to adapt interventions to address the needs of the diverse set of companies.