ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
As copper technology moves from pilot to volume manufacturing, semiconductorfabrication is focused on methods to improve device yield. In especially semiconductormanufacturing, electrochemically deposited copper is the material of choice for advancedinterconnect applications. Electrochemical deposition (ECD) employs copper plating electrolyteswith organic additives to achieve bottom-up filling of small vias and trench with high aspect-ratios.However, for features with small aspect-ratios, the ECD process yields conformal layers becausethe additives and the bottom-up fill mechanism are not operative in such large features. So, ECDprocess does not achieve within-die and within-wafer planarity of the deposited copper layer. Forplanarization of large features and obtaining globally and locally flat films, an electro-chemicalmechanical deposition (ECMD) method has been employed. ECMD process is a novel techniquethat has ability to deposit planar conductive films on non-planar substrate surfaces. Techniqueinvolves simultaneous ECD roles and mechanical sweeping of the substrate surface. Copper layerdeposited by the ECMD process grows preferentially in cavities on the wafer surface yielding flatprofiles and much reduced overburden thickness. Preferential deposition into the cavities on thesubstrates surface may be achieved through two different mechanisms. The first mechanism is moremechanical in nature and it involves material removal from the top surface. The second mechanismis more chemical in nature and it involves enhancing deposition into the cavities where mechanicalsweeping does not reach, and reducing deposition onto surfaces that are swept. Planar layersobtained by the ECMD technique are suitable for low stress material removal processes. Planarlayers also yield improved parametric results in device structures after the material removal step. Inthis study, we demonstrate mechanical role of pad gives effects in ECMD process. So we evaluategap-filling and planarization between ECMD and ECD
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/52/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.326-328.389.pdf
Permalink