What Is a Photomask?

Reticle (English: Reticle, Mask ). In the process of making ICs, photolithography is used to form patterns on semiconductors. In order to reproduce patterns on wafers, the principle of photomask must be used, similar to When developing photos, use negatives to copy images onto photos.

It is also called photomask or mask in the industry (English name: MASK or PHOTOMASK). Material: Quartz glass, metallic chromium and photoresist. Glue becomes a photosensitive material. The designed circuit pattern is exposed on the photoresist by electronic laser equipment. The exposed area will be developed, and the circuit pattern will be formed on the metal chromium, which will become light similar to the negative film after exposure. The reticle is then used for projecting and positioning the integrated circuit. The projected circuit is photo-etched by an integrated circuit lithography machine. The production and processing steps are: exposure, development, photoresist removal, and finally photo-etching. ^[1]

• Physical structure: Image on a chrome glass thin film covered with integrated circuit images.

• Reticle: When the chrome film can only partially cover the wafer, it is called a reticle, and the pattern is usually enlarged by 4 times, 5 times, or 10 times.

• Mask: When the image on the chrome glass can cover the entire wafer, it is called a photomask. ^[1]

  Photolithography is an important step in the manufacturing process of semiconductor devices. This step uses exposure and development to trace the geometric structure on the photoresist layer, and then passes

  Integrated circuit (English: integrated circuit, abbreviation: IC; German: integraler Schaltkreis), also known as microcircuit , microchip, chip / chip (chip) in electronics is a kind of circuit (mainly including Semiconductor devices, including passive components, etc.) are miniaturized and often manufactured on the surface of semiconductor wafers.

  The aforementioned integrated circuit in which a circuit is manufactured on the surface of a semiconductor chip is also referred to as a thin-film integrated circuit. Another type of thick-film integrated circuit (hybrid integrated circuit) is a miniaturized circuit composed of independent semiconductor devices and passive components integrated into a substrate or a circuit board.

  This article is about monolithic integrated circuits, that is, thin film integrated circuits.

  From 1949 to 1957, Werner Jacobi, Jeffrey Dummer, Sidney Darlington, Yasuo Tarui all developed Prototype, but modern integrated circuits were invented by Jack Kilby in 1958. He was awarded the 2000 Nobel Prize in Physics, but Robert Noyce, who also developed modern practical integrated circuits at the same time, died as early as 1990. ^[2]