AlN PVD for Piezo-MEMS Webinar -19 June 2018
Advances in doped AlN deposition techniques for next generation PiezoMEMS
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This webinar was presented live on Tuesday 19th June. To replay the recording, CLICK HERE (Registration will be required)
In BAW and Piezo-MEMS devices based on released membrane structures, AlN film stress state is of utmost importance and to maximize yield, manufacturers look to minimize stress variation across the wafer. When scandium (Sc) is added to the film, the problem becomes more demanding, as stress range tends to worsen with increased Sc content. Previous methods to control stress reach a limit of capability, impacting yield or compromising device design and performance. The problem is compounded when variations in Sc content exist in the film centre to edge, either as a result of chamber geometry, or sputter target homogeneity, impacting resonator film properties, such as coupling coefficient.
In addition to stress control, a related issue presents itself when Sc is added to an AlN film. During deposition, crystallites can form within the AlScN. Effectively defects in the film, the crystallites degrade resonator performance. Formation is abundant in areas of tensile stress, hence the relation to stress control. As with stress profile, crystallite density increases with Sc content so management of crystallite formation becomes another requirement for the PVD process, to ensure coupling coefficient yields are maximized.
In this webinar we present a novel solution providing symmetrical control and adjustment of stress for AlN films with different Sc content. We demonstrate excellent WIW stress performance, the ability to locally tune stress to compensate for center to edge variations in Sc, and approaches to prevent formation of crystallite defects, maximizing yield.
Dr Anthony Barker
Anthony Barker joined Surface Technology Systems (STS) in 1997 as Etch Process Engineer. He went on to manage STS’ non-Si based etch and deposition process groups. After leaving STS he joined Trikon as Etch Process Engineer in 2005, which became Aviza Technology and then merged with STS in 2009 to form SPTS Technologies. Most recently Anthony worked as Principal Process Engineer in R&D Accounts group before joining SPTS's PVD Product Management team in May 2017. Before STS, Anthony worked as Thin Film Process Engineer at Gems Sensors. Dr Barker has a B.Eng Honours degree in Materials Engineering and a Ph.D in Electronic Materials in association with Rolls Royce, both from Swansea University.