What Is Semiconductor Manufacturing?
Semiconductor manufacturing is used to manufacture semiconductors used in transistors and integrated circuits.
Semiconductors are used not only in personal computers and smartphones, but also in cloud services, data centers, and many other electronic devices. Technical innovation of semiconductors is progressing while taking into account information storage, numerical calculation, logical value computation, and the fast processing speed of these processes, energy saving, and space saving aspects of semiconductors.
Semiconductor Manufacturing is essential for dramatic progress in line with the higher performance and technological innovation of semiconductors.
Uses of Semiconductor Manufacturing
Semiconductor manufacturing, as the name implies, is used for manufacturing semiconductors. Major semiconductor components include transistors and diodes, which are individual elements used to electrically control the flow and direction of electricity in equipment, CPUs that control the arithmetic processing of programs and other data in equipment, as well as memory that stores programs and other data.
Semiconductor manufacturing is also used for CMOS image sensors used in cameras.
Principle of Semiconductor Manufacturing
The basic operations of Semiconductor manufacturing can be categorized into Circuit Design & Pattern Design, Photomask Making, Front-end Processes, and Back-end Processes.
1. Circuit Design and Pattern Design
Circuit and pattern design involves designing circuits that realize the required functions and studying efficient patterns by running simulations many times. For pattern design of semiconductor devices, dedicated CAD software is used.
2. Photomask Creation
Photomask creation is the process of creating an original plate for transferring a circuit pattern onto a semiconductor wafer. Transistors and wiring on the surface of a semiconductor wafer are extremely detailed, and the circuit pattern is enlarged and drawn on the surface of a transparent glass plate.
3. Front-End Process
The front-end process is up to the creation of chips on silicon wafers. This series of processes includes cleaning, photolithography, etching, film deposition, ion implantation, and planarization, and is repeated many times.
4. Back-End Process
The back-end process is from the semiconductor chip made on a silicon wafer until the chip is completed by subdividing it into smaller pieces. Each process includes dicing, die bonding, wire bonding, molding, and inspection.
Types of Semiconductor Manufacturing
Semiconductor Manufacturing Equipment can be broadly classified into Semiconductor Design Equipment, Photomask Manufacturing Equipment, Wafer Manufacturing Equipment, Wafer Process Processing Equipment, Assembly Equipment, Inspection Equipment, and Related Equipment for Semiconductor Manufacturing Equipment.
1. Semiconductor Design Equipment
Dedicated CAD software has been developed for circuit and pattern design.
2. Photomask Manufacturing Equipment
A photomask, also called a glass dry plate, is a glass or quartz plate on which the original pattern plates used in the manufacturing process of electronic circuit components are formed. Photomask manufacturing equipment deposits a light-shielding curtain such as chrome on a glass substrate and draws a circuit pattern using a laser or electron beam. Developers, dry etching equipment, and inspection equipment are also used.
3. Wafer Fabrication Equipment
First, silicon single-crystal ingots produced to ultra-high purity are cut to a specified thickness by cutting equipment using diamond blades. This is the silicon wafer. Next, the surface of the wafer is polished and placed in a high-temperature oxidation furnace to create an oxide film. A photosensitive agent called photoresist is then applied to the wafer surface using a resist coater/developer.
Circuit patterns are formed by scaling and burning photomask images onto the surface of a wafer. Semiconductor exposure systems are used for this process. In addition, etching and stripping equipment removes unnecessary oxide film and resist.
Ion implantation and annealing equipment is used to implant boron, phosphorus, and other substances into the wafers to make them semiconductors. The wafer is then placed in a plasma system, where inert gas plasma forms an aluminum metal film for electrode wiring on the wafer surface. Finally, wafers are tested chip by chip in the inspection equipment to determine whether they are good or defective, and the previous process is completed.
4. Processing Equipment for Wafer Process
In the back-end process, wafers are first cut and separated into individual chips by dicing saw equipment. The chips are then fixed in place on the lead frames.
5. Assembly Equipment
First, die bonder equipment is used to connect the chips to the lead frame using bonding wire. Next, the chip is packaged with resin using a molding device for protection. Then, individual semiconductor products are cut and separated from the lead frames using a die, and the external leads are formed into a predetermined shape.
6. Inspection Equipment
To exclude initial defects, an accelerated temperature-voltage stress test, called burn-in, is performed while performing function tests. Finally, electrical characteristic tests and visual structural inspections are performed to remove defective products. Reliability tests such as environmental tests and long-term life tests are also required.