By the end of 2018, the semiconductor industry is expected to grow to $451 billion, an increase of 7.5% from 2017. With more innovative technology and electronic devices expected to reach the market within the next five to 10 years, semiconductor manufacturers should prepare for growth and examine production solutions for future applications, including thin film deposition techniques.
Types of Semiconductors
Semiconductors come in two forms: intrinsic and extrinsic. Intrinsic semiconductors consist of two subtypes: pure semiconductors and compound semiconductors. Pure semiconductors, like silicon, are at the heart of all electronics. Compound semiconductors, on the other hand, are crucial to optical applications such as LEDs (light-emitting diodes), photodetectors, IR detectors, and focal plane arrays.
Both types of intrinsic semiconductors are chemically-pure materials with conductivity between an insulator and a conductor. “Doping” is performed to adjust conductivity. Doping is the process of adding specific atomic impurities to a semiconductor, therefore creating extrinsic semiconductors. By stacking layers of different types of intrinsic and extrinsic semiconductors, devices such as diodes, transistors, and thermistors are built. Both pure semiconductors and compound semiconductors can become extrinsic.
Extrinsic semiconductors are used in practical applications because their conductivity can be controlled. When impurities are added, it modifies the semiconductor’s electrical properties, making it suitable for use in diodes, transistors, light emitters, detectors and other devices. They can also be split into two subcategories of their own: n-types and p-types. N-type semiconductors have excess (negatively charged) electrons, while p-types have positively charged “holes” (missing electrons). Both of these excess carriers conduct current.
Drivers of Semiconductor Growth
There are several reasons we can expect continued growth in the semiconductor sector, and nearly all of them center around consumer technological advancements. In our ever-connected world, the demand for faster speeds and efficient power sources is always increasing.
5G mobile communications: The advent of 5G cellular networking isn’t here quite yet, but we do know that it’s coming, and it’s the next step forward in mobile technology. Currently, we use 4G LTE (Long Term Evolution) networks to download data on our smartphones and tablets; 5G is the data standard of the future, and it’s expected to bring a marked increase over LTE in network speed and data capacity. 5G data centers will inevitably have higher power consumption requirements, which is where more sophisticated semiconductors will be needed. New smartphones and other devices will also need to be developed for 5G, and so will the semiconductors that power these devices, which will in turn drive demand for chip production.
5G is critical to other growth areas, including IoT (Internet of Things), machine-to-machine communication, and “smart” autonomous vehicles.
Newer features and efficiency: 5G is expected to be the main driver of device improvements and capabilities, but there are other consumer needs at play. Longer battery life and energy efficiency are always in demand, so semiconductors that help deliver these capabilities are needed as well. As artificial intelligence (AI) trends upwards and becomes more of a staple in smart devices, there’s also a bigger need for AI capability, driving demand for faster, smarter chips with more memory and storage capacity.
Newer technologies: Along with newer features, newer devices and technologies are being developed and adopted on a global scale, all of which require semiconductors to run. Here are just a few new applications where we can expect to see semiconductors implemented in the coming years:
- Drone technology and unmanned aerial systems
- Autonomous vehicles
- Virtual reality (VR) and augmented reality (AR) devices and technology
- Solid-state refrigeration & cooling
Solving Semiconductor Challenges with Thin Film
There are several design challenges facing the semiconductor industry that thin film coatings will address. With more and more devices connecting to and thriving on the IoT (Internet of Things), security is a concern, as is wireless connectivity and speed. Smaller form factors and lower power consumption are other goals that companies will need to hit. Water-resistant or waterproof mobile devices are a huge draw for consumers, so those are important features for semiconductor chips; devices need to be reliable and durable, withstanding constant, prolonged use and occasional rough handling.
Thin film deposition can help solve these challenges across the different levels of the semiconductor package. At the die/chip level, anti-reflectivity (AR)/high-reflectivity (HR) coatings are critical for laser diodes. Contacts on the device itself require metallic layers. The semiconductor chip then needs to be packaged to the transistor array, and indium bump deposition is the optimum method to achieve high shear strength and high pixel density.
For the finished consumer product, diamond-like carbon (DLC) coatings can provide maximum protection against scratching and breaking of the components. DLC coatings should also be applied to outer displays, such as phone screens, for the same protection. To waterproof the finished products, hydrophobic coatings can be applied on either the chip or device level, providing manufacturers with multiple options to achieve water resistance, depending on the cost of production and performance goals.
Compound semiconductor chip coatings also need to meet specific optical properties. Ion assisted deposition (IAD) and ion beam deposition (IBD) allow for tighter control of specific properties during the deposition process, so they are both good methods to keep in mind.