Filtering for 5G – AlScN deposition for the next generation of BAW filters
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This webinar was originally broadcast live on 20th May 2020. To access the recording, click the link below
The performance advantages of 5G over previous generations of mobile networks are huge. Promises of 10Gbps are still some way off but even phase 1 of 5G offers ten times the download speed of 4G. Frequency bands for 4G are generally below 4GHz, but 5G frequencies will be much higher. For the current phase of 5G, with filter bands up to 6GHz, devices will use existing technologies like Bulk Acoustic Wave (BAW) filters, which will be tested to the limit at these higher frequencies. For the later phases of 5G, filtering the millimetre wave space of frequencies above 20GHz may require novel technologies.
The resonant frequency of a BAW filter is defined by the thickness of the piezoelectric layer, notably AlN - as frequencies increase the thickness of the AlN must decrease. This causes a decrease in the output of the filter, which can be restored by doping the AlN with scandium. However, depositing thinner layers of AlScN, with higher and higher Sc concentration, is a challenge for the device manufacturer in terms of variation in the stress state across the wafer (WIW stress) and the increased likelihood of crystallite defects, also known as mis-orientated grains.
In this webinar we present the latest PVD technology solutions to deposit very thin highly doped layers of AlN. We discuss how to control the critical aspects of doped AlN deposition, like the layer thickness uniformity, the crystallographic texture of the film, the control of mis-orientated grains and most importantly the control of the stress state of the film within the wafer. We demonstrate outstanding within wafer stress performance and mis-orientated grain control for AlN layers with atomic Sc content up to 30%.
Presenter: Dr. Anthony Barker, Senior Product Manager, PVD Products.
Anthony Barker joined Surface Technology Systems (STS) in 1997 as Etch Process Engineer. He went to manager 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