Papers by Keyword: Metallic Impurities

Abstract: The paper investigates the technology of refining primary aluminum from vanadium impurities, based on flux treatment with boron-containing fluxes. In the Pavlodar region of the Republic of Kazakhstan, on the basis of local enterprises, the production of primary aluminum and products based on local raw materials is developing. The main problem in the production of primary aluminum on the basis of JSC “Kazakhstan Electrolysis Plant” is the presence of undesirable vanadium impurities, which pass into metal during electrolysis from baked anodes based on calcined coke (vanadium content up to 800 ppm) of the local enterprise LLP UPNK-PV (Pavlodar, Kazakhstan). The authors investigated the process of ladle refining of aluminum from vanadium using the Al-B (3% B) alloy. Laboratory and industrial tests have shown a decrease in the vanadium content by an average of 78% in the bulk of the metal, with an increase in its content in volume up to 5-10% of the ladle capacity. It was found that mixing leads to a certain averaging of the vanadium content in the ladle volume.

Abstract: Micro-contamination exerts ever-increasing adverse impact on semiconductor manufacturing as device integration scale keeps increasing and device geometry continues decreasing. In particular, contaminations from particles, trace metals, and/or organic compounds can reduce device yield, quality, and reliability ^[. Metallic impurities from materials used for process equipment are one of the major contamination sources.

Abstract: Silicon-based power device performances are largely affected by metal contamination occurring during device manufacturing. Among the usual gettering techniques, recent developments were done on high dose helium implantation. Even though the gettering efficiency of this technique has been demonstrated in device application, the required doses are still extremely high for an industrial application. Recently, it has been shown that the use of H/He co-implantation limits the total requested doses [1]. In this paper, co-implantation of H/He, which has been already used to reduce the dose in the smart-cut® process is explored. The goal of this work is to decrease efficiently the implanted dose maintaining an efficient metallic gettering without degrading the Si surface. The impact of H implantation on He implantation induced defects is carefully studied. The TEM observations have evidenced that hydrogen addition drastically modified the defect band structure and promotes the cavity growth.. Additionally, we demonstrate that an efficient gettering can be obtained.