VACUUM PUMP FOR MANUFACTURING CHIP & ELECTRONIC PARTS
I. Vacuum application for chip manufacturing
Semiconductors are shaping our world, contributing to every aspect of human welfare. Evolutions like Cell phones, computers, the internet, and social media owe their existence to the advancements in semiconductor technology. The latest trends in Big data and Artificial Intelligence have paved the way for new growth and innovation in the semiconductor market.
Vacuum plays a vital role in realizing the semiconductor chip. From the processing of the initial raw product to the realization of the final chip, various processes involve different levels of vacuum. The various processes involved in the semiconductor industry are
· Deposition
· Etching & Cleaning
· Implantation of lon
· Handling of Wafers
· Lithography
· Wafer Inspection & Metrology
Deposition
Deposition processes create layers of dielectric (insulating) and metal (conducting) materials used to build a semiconductor device. Depending on the type of material and structure being made, different techniques are employed. The various technologies include Physical Vapor Deposition (PVD), Plasma Enhanced Chemical Vapor Deposition (PECVD), Sub-Atmospheric Chemical Vapor Deposition (SACVD), Low-Pressure Chemical Vapor Deposition (LPCVD), and Atomic Layer Deposition (ALD). Each technology requires different levels of vacuum.
The most common PVD method is sputtering technology where the inert gas ions generated by plasma are bombarded on the target material. The combination of dry roughing pumps along with turbo/cryo pumps is best suited for the PVD method.
Plasma-enhanced CVD (PECVD) and ALD are used to form the critical insulating layers that isolate and protect all of these electrical structures. Except for High-Density Plasma deposition (HDPCVD), most of the processes operate under a primary vacuum, in the mbar pressure range
LPCVD applications are typically used in semiconductor manufacturing to create Polysilicon thin films, insulating oxides, or passivation layers. Diffusion is a thermal process used for oxidation and nitration of the wafer surface, or to change the electrical properties of the doped layers.
ALD processes operate under a primary vacuum in the range of 0.1 to 5 mbar. Based on the volume of manufacturing equipment, the capacities of dry pumps can be determined so that faster evacuation with high throughput is ensured.
Etching and cleaning
The etching process results in the creation of chips after selectively removing films and materials that are deposited on the wafer. Strip and clean techniques are used between manufacturing steps to eliminate unwanted material that could later lead to defects and to prepare the wafer surface for subsequent processing. The vacuum requirement for the stripping and cleaning process is in the range of 1 mbar and high-capacity dry pumps are most suited. Due to the absence of load lock chambers in some equipment used in this process, faster pump down times are expected for high throughput
Processes like Dry dielectric etching, Conductor, and Polysilicon etching operate in the range of 0.01 to 0.001 mbar and combinations of turbopumps backed by dry vacuum pumps are mostly suited for this process. Turbopumps are connected to the chamber while dry backing pumps are placed in the basement.
Advanced etch techniques, such as atomic layer etching (ALE) are capable of removing a few atomic layers of material at a time. While conductor etches processes precisely shape electrically active components like transistors, dielectric etch forms the insulating structures that protect conducting parts.