Blog: Industry’s Best Solid-State Technology Protected by Reno’s Extensive Patent Portfolio
Reno Sub-Systems (Reno) is recognized as a leading supplier of differentiated matching network and power generator products that are enabling the semiconductor industry to move to sub-7nm process nodes. Its technologies are backed by a broad patent portfolio that covers the Solid-State Electronically Variable Capacitor-based (EVCTM-based) matching network/RF generator market segment. As its technologies have advanced, the company has kept its entire portfolio “alive” with continuations (CON) and continuations in part (CIP), with priority dates beginning Jan. 10, 2014. Reno’s portfolio currently has 58 issued and pending patents.
What patents do we own?
Of Reno’s current 35 issued patents, several of the core patents, which have priority dates of March 5, 2005, and Jan. 10, 2014, describe the basis of Reno’s Solid-State EVC PiN diode and transistor RF switching technology. PiN diodes, which were first invented in 1950, are highly reliable and are used as key switching components for equipment, such as phased array radar and magnetic resonance imaging machines. Our EVC technology is an alternative to using the traditional electromechanical approach that uses vacuum variable capacitors or other alternative solid-state switching networks, which will be described below.
- US 7,251,121 ELECTRONICALLY VARIABLE CAPACITOR ARRAY
- US 9,196,459 RF IMPEDANCE MATCHING NETWORK
- US 9,496,122 ELECTRONICALLY VARIABLE CAPACITOR AND RF MATCHING NETWORK INCORPORATING SAME
- US 10,026,594 RF IMPEDANCE MATCHING NETWORK
These core Reno patents cover the design of the Solid-State EVCM and the use of both series and shunt EVC designs with L-, pi-, T-, etc., configurations. Reno’s patents prevent a competitor from using a matching network that uses multiple EVC devices, whether they are L-configuration, pi-, T-, etc., which alters the EVCM capacitance based on a parameter related to the plasma chamber.
US 9,496,122 was challenged twice in court with an inter partes review (IPR), brought by a competitor, and the court turned down its alleged invalidation attempt. US 10,026,594 received a third-party submission to the United States Patent Office, attempting to challenge the patent claims, yet our patent was granted. These actions substantiate the validity and importance of Reno’s core Solid-State EVC technology.
What does this mean to you?
Plasma impedances vary with power, gas, flow, pressure, temperature, bias, etc. An RF matching network needs to convert these varying plasma impedances to a stable impedance that matches the RF generator’s output impedance of 50 Ohm. Reno uses a Solid-State EVC matching network, which is a digital array that switches capacitance in ~10 µsec and offers auto-tune matching in less than ~500 µsec. This run-to-run repeatable and accurate instantaneous match technology enables the precise, high aspect ratio, selectively anisotropic sharp-edge plasma processing required for today’s and tomorrow’s devices, including 3D structures. Reno’s patented EVC matching networks reduce match time, widen the process window, increase plasma stability and deliver the exact amount of RF power to every wafer, every lot, on every tool. As one of our customers stated, “Reducing RF variability in the plasma process offers the largest opportunity to improve productivity and yield.”
Why is Reno’s approach better?
- One alternative solid-state switching network uses a bipolar junction transistor (BJT)/insulated-gate bipolar transistor (IGBT) diode-based switch that is typically limited to a handling capacity of 2 Amp, compared to Reno’s 17 Amps. This allows Reno to design much higher power handling capacity. Also, a matching network based on a BJT/IGBT diode switch has a much lower efficiency than the Reno PiN diode-based matching network.
- Another technology used is the metal oxide semiconductor field-effect transistor (MOSFET) diode-based switches. When unbiased low-cost diodes are used, they produce RF distortion, which will impact plasma performance and stability. Compared to this approach, Reno’s PiN diode or MOSFET-based designs do not produce any RF distortion.
- Alternative solid-state technology shows wide variations (~7ms) in match times. Compared to this, Reno’s matching networks have proven, on-plasma repeatability of 0.5ms or less. For short processes, such as in an atomic layer deposition type of system, where RF ON times could be 50ms to 100ms, 7ms of variation has a significant impact on plasma stability, process repeatability, and yield.
Who is behind this expansive patent portfolio?
Dr. Imran Bhutta, Reno’s founder, chief technologist and president, is the principal inventor of Reno’s technology. He has currently been awarded 27 patents over his 25-year career in solid-state networking technology. An additional nine other inventors have contributed and are named on our patent portfolio, showcasing the depth and breadth of RF talent at the company.
The Belles Group, a small Philadelphia, Pennsylvania boutique patent firm with a focused group of patent attorneys and paralegals who specialize in Reno’s technology space, have written and prosecuted all but the very first Reno patent.
Reno’s patent portfolio is assigned to Reno Technologies, Inc., which is a wholly owned subsidiary of Reno Sub-Systems, Inc. Alan Walter, president of Reno Technologies, Inc., manages the IP portfolio, drawing on his more than 37 years of experience as an inventor and managing executive of semiconductor equipment patent portfolios. Walter also oversees patent prosecution and litigation for the company.