The other side of Moore's Law - where is More than Moore headed?
More Moore and More than Moore Lead the Semiconductor Industry
"Moore's Law" is at the heart of the semiconductor industry, reducing transistor size at the "node" and is dominated by a single focus and relentless drive to integrate small, fast transistors on each chip.
In contrast to "More Moore", which aims to improve performance by miniaturizing such transistors, "More than Moore" devices are digital electronics meeting the analog world. , represents the diversification of new capabilities in technology and is on the verge of a dramatic expansion with the emergence of various new applications, from 5G, IoT and autonomous driving technology to neural sensors.
Also, while many semiconductor manufacturers still focus on size, speed, and power, you don't necessarily need all the cutting edge technology to create the best geometry at the cutting edge node. You should understand that it is true.
What are the technical challenges of More than Moore?
The technical challenges faced by chip manufacturers in More than Moore are not terribly difficult, but the requirements are different in each case, such as the use of unique structures and materials different from silicon. I will come. In many cases, such devices have been manufactured using manufacturing equipment and process applications developed for large nodes of silicon semiconductors, but are now evolving with new technologies and cutting-edge knowledge.
Let's take a look at the types of chips and circuits needed to communicate information between reality and digital, and the manufacturing challenges they present.
Sensors and Transducers
Sensors and transducers convert variations in physical quantities into electrical signals and vice versa. The quantities they convert, temperature, pressure, motion, etc., and the signals they produce are typically analog. It changes continuously according to the range of values.
The value of the sensor changes according to the amount it perceives. Modern cars are equipped with hundreds of sensors that monitor everything from the fuel mixture needed in the engine to carbon monoxide levels inside the vehicle. An accelerometer detects a collision and deploys the airbags. A gyro sensor detects displacement. Self-driving cars are equipped with a huge number of sensors to grasp the surrounding situation. Sensors in next-generation smartphones will enable 3D recognition of fingerprints for anti-hacking purposes, and high-sensitivity microphones will respond to commands to home automation systems. Biomedical sensors can monitor not only a person's health, but also what they think and how they think.
Many sensors are manufactured using silicon and processes similar to materials used in semiconductor manufacturing as MEMS (MicroElectroMechanical Systems), but the processing dimensions are much larger than semiconductor devices manufactured with silicon. Thing. It has been shown that even such an accelerometer and gyro can achieve high performance. 3D fingerprint sensors and high-sensitivity microphones are achieved by using advanced piezoelectric material elements that require new processes, deposition and etching techniques.
Analog and Mixed Signals
Most of the electrical signals output from sensors are usually voltages and currents that have been converted to analog waveforms. In order to utilize them, various adjustments such as amplification and filtering are necessary, but this is the work of analog circuits. These analog circuits are also used in other situations, such as amplifying the audio signal sent to the speakers of a sound system.
Another important analog application is wireless communications such as Wi-Fi, Bluetooth, and radio frequency signals such as those used for radar in driver assistance systems. Analog circuits are not always beneficial for small geometries. Analog circuits can be very difficult to design and manufacture because a combination of slight changes in one component can have unpredictable results in the overall circuit.
Mixed-signal circuits combine digital and analog components. Any device that converts an analog signal to digital or vice versa must be mixed signal.
The need for these types of circuits is growing rapidly as device users demand more functionality with fewer chips. The manufacturing process for forming different types of transistors on the same chip, such as bipolar for analog, CMOS for digital, and DMOS for power supply, has different requirements from CPUs, which account for a large proportion of digital circuits.
Nevertheless, mixed-signal circuit manufacturing is currently transitioning from 200mm wafers to 300mm wafers, and is a platform (bridge) for manufacturing tools designed when a similar wafer size transition occurred in CMOS processes. It is a candidate as a tool).
Power
Power supply and management is an essential requirement for any device. From high-power devices for wind turbines and high-speed trains to fast-charging and high-power devices found in electric vehicles, fast-charging and power management are also required for small mobiles and palm-sized devices. It's a requirement.
Each of these uses a different technique. Some contain thin vertical structures with large lateral dimensions. Others are based on wide-gap semiconductors such as GaN and SiC.
About 15 years ago, Lam Research commercialized the Versys Kiyo45 etching equipment (RIE) for 300mm wafers. In recent years, this equipment has been able to handle 200mm wafers in line with the growing needs for etching GaN and AlGaN substrates, and is being used as a bridge tool.
Optical Communications and Optoelectronic Devices
As networks begin to migrate to 5G communications, the need for optical devices to achieve higher line speeds will increase. These devices are used to convert optical and electrical signals, and laser diodes and LEDs are mainly used. As an unusual example, there is a movement to use small LEDs (micro LEDs) as displays for smartphones, and development is currently underway.
Such optical devices, such as photodetectors, receive light as a signal and convert it into electricity. Electro-optic modulators (EOMs) are used to adjust the phase phase, frequency, amplitude, polarization, etc. of optical signals. And the optical isolator prevents the reflected return light, and the waveguide routes the signal inside the chip.
Active optical communication and optoelectronic devices are often built with wide-bandgap compound semiconductors, whereas passive devices like waveguides are essentially silicon-based. These require a high level of wafer-to-wafer wavelength uniformity and tight control of optical properties such as refractive index during the manufacturing process.
With the rapid proliferation of connected devices, a myriad of new application areas such as portables, wearables, IoT and 5G communications, cloud storage, and autonomous driving technology are creating needs for specialized manufacturing equipment. Many of these devices do not require the finer processing of advanced nodes and can be built on systems that were introduced at older nodes with lesser technology. However, it should be remembered that many of them require specific tweaks and selective enhancements utilizing new technologies and cutting-edge knowledge.