Many gettering techniques have been widely studied to overcome this problem by removing metal impurities from active regions of device . one new gettering method that has recently received growing interest is the use of nanocavities resulting from helium or hydrogen implantation 所以需要減小有源區(qū)中金屬雜質(zhì)的濃度,通常采用吸除的方法把金屬雜質(zhì)從器件有源區(qū)吸收到有源區(qū)之外預先形成的sink(陷阱)中。
Metal impurities unintentionally introduced into si wafers during various device process steps are very harmful to device performances . many gettering techniques have been widely studied to overcome these problems by removing metal impurities from the active region of a device . reduction in device size and introduction of new moralization processes require more efficient gettering techniques working at lower temperatures 半導體工藝中無意引入的金屬雜質(zhì)的污染會極大損害器件性能,為了將金屬雜質(zhì)從器件的有源區(qū)吸除,吸雜技術被廣泛的研究,器件尺寸的不斷縮小和新的金屬化工藝的不斷出現(xiàn)更需要能在低溫有效吸除的技術。
To avoid manual labor of chiseling-grossness, in the area of second-stage concrete construction, permanently non-removed metal molding boards nets are used as molding boards of first-stage concrete . substitution joints of reinforcing steel bars for traditional electric welding and usage of equipments for joints of reinforcing steel bars efficiently improve strength of junctions and rate of connecting reinforcing steel bars, and safety of construction and stability of quality, and greatly reduce cost . it's possible that three gorges project become top-ranking project in the world by study on systems engineering of high-strength concrete construction 混凝土縫面處理采用高壓水流沖毛技術,大大提高了施工工效,減少了倉面污染;模板工程大量采用定型鋼模板施工技術,提高了壩體混凝土成型質(zhì)量和工程進度;在二期混凝土施工區(qū)域,為免除人工鑿毛勞動強度,采用永久性免拆金屬模板網(wǎng)作為一期混凝土模板;鋼筋連接改進傳統(tǒng)的電焊連接方式,采用大量采用鋼筋接頭機械連接技術,有效提高了接頭強度和鋼筋連接速度,施工安全性大大加強,質(zhì)量穩(wěn)定性有效提高,經(jīng)濟成本大大降低;三峽二期工程持續(xù)高強度混凝土施工系統(tǒng)工程的研究,使三峽工程成為名符其實的“世界一流工程”成為可能;三峽二期工程混凝土溫控綜合技術的應用,有效降低了壩體混凝土溫度的產(chǎn)生;混凝土表面處理及裂縫處理技術的應用,提高了建筑物的整體性和耐久性。