Tag Archive HR-SOI

ByAdministrator

RF-SOI: Already in Every Smartphone, New Opps Abound in IoT (SF Workshop Part 3 of 3: IBM, ST, GF and more)

RF-SOI is already found in virtually every new smartphone out there, so the RF-SOI session of the recent FD-SOI/RF-SOI Workshop in San Francisco focused on long-term growth and further opportunities.

In case you missed it, ASN already covered the SF Workshop’s FD-SOI presentations (Samsung, ST and the EDA houses – click here for that post) and the panel discussion (where we learned Cisco is working on an FD-SOI chip – click here to read that post). As we mentioned there, the workshop was a huge success, with over 150 people from over 80 companies in the audience.

The presentations are becoming available on the SOI Consortium website, so keep checking there. (Also, if you want to know more about how the special wafers for RF-SOI solve design challenges, Soitec contributed an excellent ASN article a couple years ago – click here to read it.) But for now, here’s a brief recap of the RF-SOI presentations.

IBM

IBM has been offering RF-SOI foundry services since 2007 and recently said it shipped more than 7 billion RF-SOI chips in the last 3 years (read more about that here). Clearly they are experts in this business. In his talk, RF-SOI: Redefining Mobility and More in the Front-End, Mark Ireland, VP of Strategy and Business Development, Microelectronics Division, IBM Systems & Technology Group, said that LTE is the fastest developing mobile system technology ever. A big driver is mobile video: the CAGR there is 66% over the next five years, and it’s happening on both high-end and low-end smartphones.

IBM_RFSOI_LTE

 

Next comes IoT as an RF-SOI driver, and he gave a roadmap and examples.

IBM_RFSOI_IoT

He also looked at demand for RF-SOI wafers, which are typically 200mm, but he noted that 300mm is starting to sustain growth, too.

IBM_RFSOI_wafers_lowres

(You might also want to also refer to the IBM RF-SOI presentations given recently in Shanghai and Tokyo.)

ST

In her presentation entitled, ST H9SOI_FEM: 0.13µm RF-SOI Technology for Front End Module Integration, Laura Formenti, Infrastructure and RF-SOI BU Director, STMicroelectronics focused on front-end module (FEM) integration (ST contributed an excellent article on this to ASN last summer – you can read it here). She made the link between new opportunities in RF-SOI and new developments by Soitec in RF-SOI wafers.

ST_RFSOI_roadmap

Putting power amplifiers (PA) on RF-SOI is starting to happen, and she provided data showing that they’re now closing in on GaAs in terms of performance.

ST_RFSOI_PA

ST is offering H9SOI_FEM on a foundry basis and as a partner. They can deliver prototypes within three weeks, and provide full integration up to packaging. (While you’re waiting for this presentation to be posted on the SOI Consortium website, you might want to refer to a similar presentation given recently by ST in Tokyo.)

GlobalFoundries

In SOI: An Enabler for RF Innovation and Wireless Market Disruption, Peter Rabbeni, Director of RF Segment Marketing at GlobalFoundries, focused on the value of SOI in RF, and explained why it presents an important opportunity for innovation at the system level.

GF_RFSOI_why

GF is the foundry partner for Peregrine (now part of Murata), and he showed how the GlobalONE PA integration is an excellent example of innovation opportunities.

GF_RFSOI_Peregrine

With an example of tunable filters, he also posited that the combination of FD-SOI and RF-SOI is a way to create disruption in wireless markets.

GF_RFSOI_FDSOI_filters

 

Incize

Incize is a spin-off of UCL in Belgium, which is a powerhouse in RF characterization. In fact, Soitec’s trap-rich SOI wafers, which are now being commercialized under the eSI moniker and launching a veritable RF revolution, were developed in partnership with UCL (you can read about that here). In his presentation entitled RF SOI: from Material to ICs – an Innovative Characterization Approach, Incize CEO Mostafa Emam explained non-destructive characterization for RF. Incize is currently working with eight customers, including wafer manufacturers. He highlighted the value of RF-SOI, and showed the characterization of Trap Rich vs. previous generations of high-resistivity (HR) SOI.

Imec

Barend Van Liempd, PhD Researcher at IMEC (Perceptive Systems dept.) / Leuven & Vrije Universiteit Brussel (VUB) (ETRO dept.,) gave a talk entitled Towards a Highly-Integrated Front-End Module in RF-SOI Using Electrical-Balance Duplexers. (He also presented this in a paper at ISSCC a few days prior.) He covered a highly integrated FEM program at Imec based on IBM technology and Electrical-Balance Duplexers.

More Workshops Coming

If you’d like to learn more about RF-SOI and/or FD-SOI, members of the SOI Consortium have been organizing these workshops around the world for the last six years (all the presentations from all the workshops are available here) and each one builds the momentum. But the workshops over the last six months (in Shanghai, Tokyo and now San Francisco) have taken that momentum to new levels. So keep an eye out for upcoming events throughout the coming year, where more and more users will be sharing their FD-SOI and RF-SOI design experiences.

ByGianni PRATA

Soitec receives Sony’s Best Partnership Award for its support with RF-SOI substrates

(Courtesy: Sony and Soitec)

(Courtesy: Sony and Soitec)

SOI wafer leader Soitec was awarded the Best Partnership Award by Sony Semiconductor. Soitec earned the recognition for outstanding support that has contributed to Sony’s success in the RF semiconductor market.

Soitec’s high-resistivity silicon-on-insulator (HR-SOI) wafers have long been a favorite of RF designers for 2G and 3G switches. But the company’s latest eSi substrates has taken off like wildfire, and are now used by all the major companies that make RF chips for smart phones.  The eSI wafers enable much higher linearity and isolation, helping designers to address some of the most advanced LTE requirements at competitive costs.  You can read more about the technical details of the wafers and how they were developed here and how they solve key challenges here.

“We are very honored to receive this award from Sony recognizing the long partnership between our companies,” said Bernard Aspar, senior vice president and general manager of Soitec’s Communication & Power Business Unit. “It demonstrates Soitec’s commitment to deliver the enabling substrates that support Sony’s RF devices business.”

By

Soitec’s New eSI SOI Wafers For 4G/LTE (Now in High Volume Production) Used at Most Leading RF Foundries

Soitec has reached high-volume manufacturing of our new Enhanced Signal Integrity™ (eSI) substrates, enabling cost-effective and high-performance RF devices. They are the first ‘trap-rich’ type of material in full production, and are already used in manufacturing by most of the leading RF foundries in front-end modules for 4G and LTE mobile computing and communication applications.

This is a major addition to our Wave SOI™  family of high-resistivity (HR) wafers for wireless applications. Our HR-SOI wafers have been used by market leaders for almost a decade, successfully addressing the challenges of 2G and 3G networks. But the data transfer rates of the new generation of 4G and LTE protocols called for a new substrate solution that would help designers meet the higher linearity and increased integration requirements.

Working together, Soitec and Université catholique de Louvain (UCL) developed a technique that adds a “trap-rich” layer underneath the buried oxide, which freezes the parasitic surface conduction that’s inherent in any oxidized silicon substrate. (The technical details are explained in a related post – click here to read it.) Using a set of very specific patents, Soitec applied proprietary technology and accumulated knowledge to build the new eSI product line.

eSI_SoitecUCLwafer

A new generation of HR-SOI substrate: enhanced Signal Integrity™
(eSI) (Image courtesy of Soitec)
 

Because this layer is built at the substrate level, expensive process steps such as high-energy implant and conservative design rules are not required when designing on eSI wafers. The result is a cheaper process and potentially smaller die area per function.

The eSI substrate allows RF designers to integrate on the same chip diverse functions such as switches, power amplifiers and antenna tuners with excellent RF isolation, good insertion loss and better signal integrity than traditional technologies.

Here is a table outlining some of the major performance advances in front-end module integration that the eSI substrate enables:

tab

The adoption of RF-SOI wafers for RF switches in handsets is now over 65 percent (Source: Yole Développement). The first RF-SOI power amplifiers and integrated front-end modules are being well received and gaining momentum in the market. Based on current levels of adoption and performance, increasing use of RF-SOI wafers for integrated front-end modules is expected to follow the same adoption rate as seen with switches.

eSImarkets

Looking back over the mobile revolution, we have seen the ever-increasing pressure on smart phone and device manufacturers to support increased demand for data traffic. Moving forward requires the contributions of all players along the value chain, including substrate manufacturers.

SOI substrates are playing a major role in RF applications. Soitec’s eSI product, developed and fine tuned over the past few years, is now qualified by several key customers and is already being used in volume production of mobile handsets on today’s market. Together, we are enabling the cost-effective integration of more and more functions as well as higher data throughput, smaller size, better reliability, improved performance and lower system cost.

RFSOIhistory

 

~~~

NOTE: This article was largely excerpted from a white paper entitled Innovative RF-SOI Wafers for Wireless Applications. To download the complete white paper, click here.

 

By

SOITEC and UCL boost the RF performance of SOI substrates

Soitec and a team from UCL have been working together to identify the technological opportunities to further improve the high-frequency performance of SOI substrates. Based on the wideband characterization techniques developed at UCL, the RF characteristics of high-resistivity (HR) SOI substrates have been analyzed, modeled and greatly improved in order to meet the specifications of wireless communication standards.

In 2003, UCL demonstrated the possibility of further improving the RF performance of HR-SOI substrates by minimizing or even eliminating the so-called parasitic surface conduction inherent in any oxidized silicon substrate [1]. UCL proposed a figure of merit, the effective resistivity, which helps compare the RF performance of various technological solutions as well as monitoring in-line the quality of fabricated substrates.

The effective resistivity accounts for the wafer inhomogeneities (i.e., oxide covering and space charge effects) and corresponds to the resistivity that a uniform (without oxide nor space charge effects) silicon wafer should have in order to sustain identical RF substrate losses. In other words, it is the value of the substrate resistivity that is actually seen by the coplanar devices.

Therefore, comparing the wafers in terms of their effective resistivity allows us to isolate the performance of the substrate by eliminating series losses and skin effect inside conductors. The interest of the effective resistivity as a factor of merit is not limited to the monitoring of the RF quality of the fabricated substrate but it is also a physical parameter which is used by RF designers to properly model the impact of the substrate.

A new substrate is born

Soitec and UCL have been working together to identify the technological opportunities to still further improve the high-frequency performance of commercially available HR-SOI substrates. Thanks to the introduction of an engineering substrate handle, Soitec can now provide a new flavor of HR-SOI called eSI, for enhanced Signal Integrity (see Figure 1) substrate (previously named Trap Rich) with a measured effective resistivity as high as 10 kOhm.cm [2].

New generation of HR-SOI substrate

Figure 1. A new generation of HR-SOI substrate: enhanced Signal Integrity (eSI) (Image courtesy of Soitec)

This high-resistivity characteristic, which is conserved after a full CMOS process, translates to very low RF insertion loss (< 0.15 dB/mm at 1 GHz) along CPW lines and purely capacitive crosstalk similarly to quartz substrate. It has been demonstrated that the presence of a trap-rich layer does not alter the DC or RF behavior of SOI MOS transistors [3].

Besides the insertion loss issue along interconnection lines, the generation of harmonics in the Si-based substrates has been investigated. HR-SOI substrate presents reduced harmonics compared with standard SOI substrate and the introduction of engineering eSI substrate handle leads to harmonics levels well below the wireless communication systems [4] (see Figure 2).

Harmonic distortion along a 2,146 µm-long CPW line

Figure 2. Harmonic distortion along a 2,146 µm-long CPW line when a signal at 900 MHz is injected at the input for a trap-rich HR-SOI wafer from SOITEC. The specification (specs straight line) for the harmonic distortion corresponds to that of RF switches for GSM/EDGE transmitter modules [5].

The improvement of the HR-SOI substrate brings also clear benefits for the integration of passives, such as the quality factor of spiral inductors or tunable MEMS capacitors, for the reduction of the substrate noise (crosstalk) between devices integrated on the same chip, etc.

Thanks to the introduction of eSIengineered substrate handle, the HR-SOI substrate can really be considered as a lossless Si-based substrate. eSI HR-SOI technology opens the path to further system integration in the Front End Module space as well as even more complex mixed-signal System-on-Chip (SoC).

 

 

A BIT OF HISTORYFor over 15 years, UCL’s Raskin research group has been developing high-frequency characterization techniques, which are today widely used by industry as well as other research teams. The group has been measuring advanced MOS devices (fully and partially depleted SOI transistors, FinFETs, Ultra-Thin Body and BOX (UTBB) devices, silicon nanowires, Junctionless multiple gate MOSFETs, etc.) from international research centers and companies.

UCL's Welcome platform

Figure 3. UCL’s Welcome platform: electrical characterization room of 350 m2.

The experimental platform known as “Welcome” at UCL (see video) is equipped with the latest electrical measurement equipment covering on-wafer measurements over a wide frequency range (DC up to 110 GHz) and temperature range (4K up to 300°C). UCL also has 1,000 m² in cleanroom facilities, including an SOI CMOS process (see Figure 4).

UCL's Winfab

Figure 4. UCL’s Winfab has 1000 m² of class M1 cleanroom facilities

In 1997, Prof. J.-P. Raskin presented pioneering work on the RF performance of HR-SOI substrates [6]. This paper demonstrated the great interest of HR-SOI substrates to reduce RF losses as well as the crosstalk in Si-based substrates.

In 2005, the team demonstrated the possibility creating HR-SOI substrates characterized with an effective resistivity as high as 10 kOhm.cm thanks to the introduction of a high density of traps at the BOX/HR-Si handle substrate [3]. Those traps originated from the grain boundaries in a thin (300 nm-thick) layer.

In 2011, with former PhD student Dr. Mostafa Emam, the team launched a spin-off company, Incize (www.incize.com), which offers RF electrical characterization services.

~~~~~~

[1]    D. Lederer, F. Brunier, C. Desrumaux and J.-P. Raskin, “High Resistivity SOI substrates: how high should we go?”, IEEE International SOI Conference, Newport Beach Marriott Newport Beach, CA, USA, September 29 – October 2, 2003, pp. 50-51.

[2]    K. Ben Ali, C. Roda Neve, A. Gharsallah and J.-P. Raskin, “RF SOI CMOS technology on commercial trap-rich high-resistivity SOI wafer”, IEEE International SOI Conference – SOI’12, Napa, CA, USA, October 1-4, 2012, pp. 112-113.

[3]    D. Lederer and J.-P. Raskin, “New substrate passivation method dedicated to high resistivity SOI wafer fabrication with increase substrate resistivity”, IEEE Electron Device Letters, vol. 26, no. 11, pp. 805-807, November 2005.

[4]    C. Roda Neve and J.-P. Raskin, “RF harmonic distortion of CPW lines on HR-Si and trap-rich HR-Si substrates”, IEEE Transactions on Electron Devices, vol. 59, no. 4, pp. 924-932, April 2012.

[5]    M. Carroll et al., “High-Resistivity SOI CMOS Cellular Antenna Switches,” CSIC 2009, October 2009, Greensboro, NC, pp. 1-4.

[6]    J.-P. Raskin, A. Viviani, D. Flandre and J.-P. Colinge, “Substrate Crosstalk reduction using SOI technology”, IEEE Transactions on Electron Devices, vol. 44, no. 12, pp. 2252-2261, December 1997.

By

The Promise of High Resistivity SOI for Wireless Communications Systems

ST reports on highly integrated SRAM and RF on 300mm wafers. Yield matches bulk with improved FOM.

Wireless communications systems may soon replace personal computers as a key driver of volume manufacturing.

A full CMOS 65nm Partially Depleted Low Power (LP) SOI technology has been developed at STMicroelectronics on high resistivity (HR) ( 1kOhm-cm) 300mm SOI wafers provided by Soitec. This latest work is the first to prove that 300mm HR SOI can match bulk yield, with improved figures of merit (FOM) of both digital and RF circuits, for high-volume wireless applications Read More

By

Opening the Route for Wireless SOI Systems-On-Chip

Optimization of RF circuits for high-resistivity SOI substrates facilitates multi-mode, multi-standard terminals integration.


The new generations of multi-mode, multistandards terminals increase the need to integrate digital, analog and RF functions on the same substrates using a System-on- Chip (SoC) approach. Silicon-on-Insulator (SOI), which can use high-resistivity (HR) wafers ( > 1000 ohms.cm) for the mechanical, supporting substrate (below the buried oxide), is enabling breakthroughs in designing RF circuits and integrating them with low-power, low-voltage digital. Read More

By

SOI for RF & Low Power ICs

When an RF chip is built on a bulk silicon substrate, the semiconducting properties of the silicon induce RF signal loss in the substrate. These capacitive and resistive losses negatively impact energy management.

The semiconducting properties of the silicon also induce transmission of parasitic interferences (crosstalk) (see Figure 1). Usage of an SOI substrate improves significantly the high- frequency behavior of the chip: first, because the buried insulating layer reduces part of the electromagnetic field propagation; second, because bonded SOI technology enables the use of a highly resistive (intrinsic silicon) handle wafer, dramatically reducing both resistive losses and crosstalk. Read More