By Arvind Narayanan 
Director, RF Product Line 

In the late 1980s and the early 90s, from the least expected places on earth in New York and Vermont, a quiet revolution in semiconductors was taking shape. One can’t fault even the nerdiest of all semiconductor enthusiasts for not paying attention because Moore’s law and the shrinking of silicon (Si) CMOS transistors were grabbing all the news and headlines.  

A group of engineers quietly rode the innovation wave and put the germanium (Ge) in Si bipolar junction transistors to deliver greatly improved device characteristics resulting in a promise for supreme RF and high-speed analog transistor performance. Their pioneering work using graded-Ge SiGe base transistors set the foundation for the commercial success of SiGe BiCMOS technologies on 8-inch wafers for various RF/Wireless and mmWave communications applications – the kind of success and the broad adoption that is rivalled only by a handful of semiconductor technologies like bulk CMOS, Gallium-Arsenide (GaAs) and RF Silicon-on-Insulator (SOI).  

While GF has been at the forefront of SOI technology innovation over the last 15 years, the legacy and the responsibility of being the torchbearer for SiGe BiCMOS technology advancement has been with GF’s (previously, IBM Microelectronics) technology developers and engineers for over four decades. Let’s trace down the history a bit more, relive and see what’s next in the story of SiGe, which the forefathers rightfully called “a story of persistence” [1].  

GF SiGe History:  A story where the sum of its parts is greater than the whole 

“A not so humble beginning” 

The first part of any series is usually the one that leaves a lasting impression, and GF’s first commercially successful SiGe technology fits the bill. More than a decade ago, the 0.35um SiGe BiCMOS technology [2] called SiGe5PAe set the stage for the entry of SiGe in the Wi-Fi power amplifier (PA) space just as the smartphone era was kicking off its world domination. This technology helped PA designers deliver the best combination of technical figure-of-merits (FoM) such as high output power, linearity and efficiency at the lowest cost.  

As demand for Wi-Fi grew and new Wi-Fi standards pushed for ever more stringent performance requirements, GF continued to deliver improvements on the base platform with various flavors of SiGe5PAXe and SiGe5PA4, including the high-resistivity substrate options that enabled full front-end ICs that integrated RF switches and Low-noise amplifiers (LNA) with a PA. Each flavor pushed the boundaries of Wi-Fi PA performance further by delivering improved PA performance while enhancing PA reliability and ruggedness for advanced WiFi standards. Table-1 shows the key features in GF’s 350nm SiGe BiCMOS technologies enabling the different applications and segments. 

What began as a humble endeavor turned out to be a huge commercial success with GF’s 0.35um SiGe technologies delivering seamless Wi-Fi experiences on high-end smartphones and tablets. Today, these technologies continue to dominate the PAs used in Wi-Fi Front-end-modules (FEM) in smartphones and have gained traction in Wireless Infrastructure applications such as PA pre-drivers.  

“One giant leap in Space and beyond” 

Usually, sequels are rarely better than the original story or series. But there are exceptions, such as GF’s 130nm SiGe technologies which are proof points for enabling several products and applications in both wireless and wired communications space [3] [4]. The high-frequency and high-voltage handling nature of SiGe heterojunction bipolar transistors (HBTs) in these technologies enables diverse applications such as mmWave and SATCOM PAs and LNAs, automotive radars, wireless backhaul and high-speed analog interface drivers.  Specifically, GF’s SiGe8WL, SiGe8HP and SiGe8XP technologies pioneered the integration of high performance NPN transistors with high-quality mmWave and distributed passives such as transmission lines and microstrips that enabled the aforementioned applications. 

“When conquering space is not enough”  

In 2014, GF’s pioneering SiGe innovation led to the introduction of world’s first 90nm SiGe BiCMOS technology in SiGe9HP [5] which was followed with another industry-leading NPN performance enhancement via SiGe9HP+ [6]. Today, both these technologies combine to form one of the most comprehensive and competitive SiGe technologies available in the market. With advanced CMOS integration and a host of features including low-loss metallization and high-voltage LDMOS, the technology enabled state-of-the-art datacenter applications, such as transimpedance amplifiers (TIA) and drivers for high-speed optical communications, and other high-performance analog applications such as high-bandwidth analog to digital converters (ADCs) and terahertz imaging and sensing. 

“There is no endgame to revolution” 

With the advent of generative AI there is no lack of appetite for higher bandwidth, data rates or longer range for communications. At GF, after four decades of consistent innovation, we are once again ready for the next revolution in SiGe technologies serving the modern communication requirements. Recently, GF published the industry’s highest performing SiGe HBT with 415/600 GHz ft/fmax on a 45nm SOI platform [7] and is actively engaging with early customers on industry’s first-ever high-performance complementary 130nm SiGe BiCMOStechnology in 130CBIC via the Globalshuttle Multi-Project Wafer (MPW) program. The key features of 130CBIC enabling a broad set of applications are shown in Table-4. 

Looking into the future, one vector of growth could be increasing the ft/fmax of HBTs further to satisfy the advanced optical transceivers requirements for datacenter optical networks and generative AI applications. However, as GenAI seeps into smartphones, there is a logical need to lower power consumption or increase RF performance (lower-noise and higher gain) at the existing power levels for RF Front-end modules or related components. Also, as broadband internet access continues its march to far reaching corners of the globe, SiGe HBT performance and cost can be optimized for consumer satellite ground terminal applications helping connect the next 4 billion users to the internet.  

While CMOS hits the wall on Moore’s Law, the true potential of SiGe can be unlocked further and realized in much larger economies of scale for applications that demand unforgiving RF / high-speed performance and capabilities. 

To find out more about how GF’s SiGe technologies can support your next-generation RF and high-performance applications, you can contact us anytime through gf.com.  

---

Arvind Narayanan is the Director of Product Management with the RF Product Line at GlobalFoundries. He owns the SiGe and RF GaN strategic roadmap and manages the related portfolio of products.  He has been with GlobalFoundries for over six years in various customer-facing roles. 

References: 

[1] D. L. Harame, B. S. Meyerson, “The Early History of IBM’s SiGe Mixed Signal Technology,” in IEEE Transactions on Electron Devices, Vol. 48, No. 11, November 2001. 

[2] A. Joseph et al., “A 0.35 gm SiGe BiCMOS Technology for Power Amplifier Applications”, IEEE BCTM 2007. 

[3] B. A. Orner et al., “A 0.13 µm BiCMOS technology featuring a 200/280 GHz (fT/fmax) SiGe HBT,” in Proc. IEEE Bipolar/BiCMOS Circuits and Technol. Meeting,2003, pp. 203-206 

[4] P. Candra et al., “A 130nm sige bicmos technology for mm-wave applications featuring hbt with fT / fMAX of 260/320 ghz,” in IEEE RFIC Symposium, pp. 381–384, 2013 

[5] J. J. Pekarik et al., “A 90nm SiGe BiCMOS technology for mm-wave and high-performance analog applications,” 2014 IEEE Bipolar/BiCMOS Circuits and Technology Meeting (BCTM), Coronado, CA, USA, 2014, pp. 92-95 

[6] U. S. Raghunathan et al., “Performance Improvements of SiGe HBTs in 90nm BiCMOS Process with fT/fmax of 340/410 GHz,” 2022 IEEE BiCMOS and Compound Semiconductor Integrated Circuits and Technology Symposium (BCICTS), Phoenix, AZ, USA, 2022, pp. 232-235 

[7] V. Jain et al., “415/610GHz fT/fMAX SiGe HBTs Integrated in a 45nm PDSOI BiCMOS process”, 2022 IEEE International Electron Devices Meeting (IEDM), pp. 266-268  

By Kevin Soukup 
Senior Vice President, Silicon Photonics Product Line  

GlobalFoundries (GF) first introduced our revolutionary GF Fotonix™ platform in 2022 with a focus on optical interconnects. The platform was rated up to 100 gigabits per second per wavelength (100G/λ) via PAM4 signaling. With an extremely fast data rate and up to 10,000x improvement in system error rate, our first-generation GF Fotonix platform was an important step forward in enabling optical chiplets that deliver faster, more efficient data transmission.  

These achievements proved successful and have established GF as a leader in the silicon photonics space, but we didn’t stop there. Let’s take a look at some of the latest advancements that we’ve made on our GF Fotonix platform, including increased design flexibility, bandwidth upgrades and full turnkey support with the development of our newly announced Advanced Packaging and Photonics Center. 

Extreme flexibility 

The GF Fotonix platform has been developed to allow customers the extreme flexibility to address various application and market segment design requirements:  

• Process flexibility: The GF Fotonix process can be run as an integrated photonics + RF CMOS flow or a photonics-only flow as required by the customer’s application and system requirements. 
• Free Form Designs: The technology allows for free-form passive component design as long as the custom devices meet the design rules. Support for custom photonic device designs is provided natively in the process design kit (PDK) through the support of technology files for the industry’s leading device simulators. 
• “Slow and wide” vs. “Fast and narrow”: GF Fotonix offers design flexibility by supporting the implementation of both course wave (CWDM) and dense wave divisional multiplexing (DWDM) to optimize beachfront density (bandwidth density along the edge of the chip). Components needed for wave division multiplexing such as athermal muxs/de-muxs and banks of micro-ring and coupled ring resonators are available in the PDK. 

From high-traffic AI data centers to next-generation advanced driver assistance systems, we are continuously working with our customers across all end markets to understand their design requirements and add the features and advancements that will take their chips to the next level. 

Doubling the bandwidth 

The second generation of GF Fotonix supports 200G/λ, doubling the bandwidth speed from the previous generation to support “fast and narrow” architectures. We’ve also made upgrades to all the active photonic devices such as modulators (micro-ring, Mach Zehnder and Ring Assisted Mach Zehnder), photodiodes and transistors to support monolithic integration. Groundbreaking progress has been made on the yield of modulator banks to support multi-lambda “slow and wide” architectures. 

The IOSMF (v-groove based passive fiber couplers) have been upgraded in two meaningful ways. First, a decrease in pitch of the individual v-grooves from 250μm to 127μm will support higher optical beach front density by 2x. Second, we’ve added support for silicon nitride (SiN) spot-size converters to improve the power handling capacity by >4x. 

With a view of the co-packaged requirements, we have been working with several vendors on wafer-level and die-level detachable fiber attach solutions. Several demos of these solutions will be showcased at the 2025 Optical Fiber Communications Conference and Exhibition (OFC) in San Francisco this April.

Finally, we have added support for thru-silicon vias (TSV) through the photonic IC (PIC). This feature allows for the 2.5D/3D stacking of the Electrical IC on top of the PIC. These TSVs can be used for high speed signaling, power delivery and heat sinking. 

Advanced Packaging and Photonics Center 

Earlier this year, GF announced a first-of-its-kind center for advanced packaging and testing at our manufacturing facility in New York. This new center will allow us to process, package and test the chips manufactured in our New York facility entirely onshore in the United States, helping us meet the growing demand for secure supply chains for our essential chips in critical end markets like automotive, communications infrastructure and aerospace and defense.  

Through this new center, GF is now able to provide a turnkey solution for our silicon photonics chips, with advanced packaging, assembly and testing services to transform chips into individual packages ready for end-product use. On the IP side, we continue to grow our GlobalSolutions ecosystem with verified and silicon-proven IP solutions from industry experts that can be easily integrated onto GF Fotonix to build your state-of-the-art, custom IC.  

To find out more about GF Fotonix and how our silicon photonics process technologies can support your next generation fiber-optic communication designs, we’ll be attending the OFC 2025 on April 1-3 in San Francisco. Join us at booth #3220 to speak with our technical representatives and view samples of packaged ICs built on GF Fotonix. We hope to see you there! 

Kevin Soukup is the senior vice president of GF’s silicon photonics product line, leading the company’s silicon photonics business that enables customers to transport enormous volumes of data through high-speed, power-efficient electro-optical systems.

By Ashish Shah 
Deputy Director, Aerospace and Defense, GlobalFoundries 

The aerospace and defense sector is experiencing rapid advancements, driven by the need for more sophisticated and reliable technologies. Within this end-market, a particular passion and focus of mine is Communications, Navigation and Identification, or CNI. GlobalFoundries (GF) radio frequency (RF) and millimeter wave (mmWave) semiconductors continue to be critical for the performance and reliability of these systems, meeting the unique demands of the A&D market. Let me tell you how and why this is the case. 

From defense to first responders 

Traditionally, radar systems have been used to identify aircraft in both commercial and aerospace and defense arenas. Over the years, there has been a shift towards phased array radar technology. Phased array radars allow for multiple beams to be broadcast and received from the same physical structure—enabling more accurate, power-efficient and cost-effective systems. In addition to tracking multiple signals simultaneously, phased array beams can be electronically steered, or beamformed, providing a larger set of capabilities than previously generations of radars. 

Due to this enhanced performance, phased arrays have become the technology of choice for this kind of beamforming. GF chips, with their RF and mmWave capabilities, are key enablers of this technology and helping to drive innovation in the radar space for both defense and commercial customers.  

Our chips are also at the forefront of the development of multi-mode, multi-standard radios, which are agile, process very wide frequency ranges and can seamlessly switch between different communication domains, such as 5G and proprietary signals, without needing multiple physical radio designs.  

This is crucial for both first responders and defense communications, ensuring reliable two-way connectivity across a range of very different environments. The radio needs to be able to dynamically search the environment and, for example, detect there’s a good 5G signal. It will use that signal while available, but when the 5G signal weakens the radar will then seamlessly switch over to a different signal, or a proprietary signal. This functionality also plays a key role in secure communications. 

Power efficient and cost-effective 

Our customers can now go from about 100 megahertz to greater than 15 gigahertz of frequency, providing a very wide aperture in the electromagnetic spectrum. This wide frequency capability allows for more efficient and cost-effective solutions, as one hardware design can be used for multiple applications, with the rest of the processing being done in software. This approach reduces the need for multiple frequency-specific designs, making it more power-efficient and cost-effective. 

The importance of this application to both first responders and national security is a great example of GF’s dual-use strategy, in which we leverage our technology for both defense and commercial applications. It enables our aerospace defense customers to leverage the economies of scale of GF’s high-volume manufacturing, but with the additional required optimization, performance and security features. 

Trusted RF and SiGe solutions 

At the heart GF’s driving innovation in CNI is our RF SOI product line, including our 45RFSOI and 45RFE solutions, which provide the higher performance from a frequency response viewpoint. This means the device can operate at the highest frequencies with a minimum amount of power dissipation, compared to other technologies. GF’s silicon-germanium (SiGe) product line, including our 8XP and 9HP platforms, are also playing a key role in CNI. These technologies bring the highest level of RF performance enabling our customers to push the frequency envelope, while ensuring the power budget is as low as possible. 

Along with optimized performance and power efficiency, our customers are also concerned with security. GF’s manufacturing facilities in New York and Vermont have Trusted Foundry accreditation and manufacture secure chips in partnership with the U.S. government. As a Trusted Foundry, with decades of experience, GF has incredibly stringent processes, equipment and oversight in place to accept classified information and manufacture classified chips in a way that ensures they are secure and uncompromised.  

And with our newly announced Advanced Packaging and Photonics Center, this capability will be expanded to post-fab services. The first of-its-kind center will offer full turnkey advanced packaging, bump, assembly and testing for aerospace and defense customers under our Trusted Foundry accreditation, allowing chips used in sensitive national security systems to never leave the U.S. during production.  

Connect with me 

At GF, we are committed to leading this charge by providing the most advanced solutions that meet the unique demands of the A&D market. The essential chips we make are optimized for mission-critical performance and reliability, and securely manufactured at our accredited Trusted facilities in New York and Vermont. 

There are so many exciting advancements in this space. I invite you to visit GF’s booth at GOMACTech 2025, on March 17-20 in Pasadena, Calif., to connect with me and our team to learn more about GF’s innovative solutions and how we can support your A&D needs. For more information, please contact me at [email protected]. Together, we can drive the future of aerospace and defense semiconductors. 

Ashish Shah is a deputy director of aerospace and Defense at GlobalFoundries. His focus in the aerospace and defense end market is on RF and mmWave technologies enabling next generation communications, navigation, and radar platforms.  

By Viswas Purohit
Principal Engineer, Process Engineering, GlobalFoundries

As we commemorate Pi Day (3.14) today, it’s not just an occasion to revel in mathematical wonder; it’s a moment to acknowledge the profound influence of the constant Pi (π) in driving technological progress, particularly in the semiconductor and chip fabrication industry. This industry, foundational to the digital age, leans heavily on Pi for precision, efficiency, and innovation. Some examples of Pi in the semiconductor industry are below.

1. Circuit Design and Optimization: In the field of circuit design, Pi is critical for calculating the electrical characteristics that determine a chip’s functionality. For instance, the formula for the impedance Z of an inductor is Z = 2πfL, where f is the frequency and L is the inductance. Designers use Pi to ensure that chips can operate at the desired frequencies, which are essential for applications ranging from basic computing tasks to complex data processing in servers, with frequencies often exceeding several gigahertz.

2. Photolithography Precision: Photolithography, the process of etching circuit patterns onto silicon, depends on Pi for calculating the exposure times and pattern dimensions with extreme accuracy. The resolution R of a photolithographic process can be estimated by R = kλ/NA, where λ is the wavelength of the light used, NA is the numerical aperture of the lens, and k is a process-dependent constant. Pi comes into play in determining the NA, which involves the refractive index and the sine of the maximum angle of the light entering the lens, showcasing how Pi governs the precision achievable in etching circuits that are mere nanometers in width.

3. Wave Dynamics and Signal Processing: Pi is integral to the analysis of electromagnetic wave propagation in chips, crucial for ensuring efficient data communication. The equation λ = c/f, where c is the speed of light and λ is the wavelength, involves Pi in calculating the wavelength for RF components, which operate in the GHz range. This precision is vital for chips in smartphones and IoT devices, where accurate signal processing and transmission are key to performance and reliability.

4. Thermal Management Solutions: Heat dissipation is a critical concern in chip design, with Pi playing a role in the formulas for calculating heat transfer and dissipation. For instance, the equation for the thermal resistance R_thermal of a cylindrical heat sink is R_thermal = ln(ro/ri)/2πkL, where ro and ri are the outer and inner radii, k is the thermal conductivity, and L is the length of the cylinder. Pi’s presence in these calculations helps engineers design chips that can efficiently manage the heat generated, ensuring stability and performance even under intense computing loads.

5. Quality Control and Testing Algorithms: In quality control, Pi is used to develop algorithms that analyze the chip’s surface and circuit patterns for defects. For example, algorithms calculating the area of irregular shapes on the chip surface to detect deviations from expected patterns employ Pi in their calculations. This precision allows for the early detection of defects in chips that may contain billions of transistors, ensuring high reliability in devices ranging from consumer electronics to critical infrastructure systems.

Concluding Thoughts: Pi Day and Semiconductor Fabrication

On Pi Day, as we celebrate this mathematical constant, it’s clear that Pi’s role extends beyond abstract mathematics into the tangible realm of semiconductor technology, where it underpins every step of the chip fabrication process. From designing circuits that power our daily-use gadgets to ensuring the reliability and efficiency of complex computing systems, Pi’s applications in semiconductor fabrication are a testament to its fundamental importance in the technological advancements that define our modern world.

Thus, Pi Day is not just a celebration of a mathematical constant; it’s a recognition of the symbiosis between mathematics, science, and technology. It highlights how Pi, a number known for its infinite sequence, delivers finite, tangible benefits to society by driving the innovations at the heart of the digital age.

Viswas Purohit is a principal engineer in process engineering at GF’s Malta, NY facility.