Browse Definitions :
Definition

photolithography

Photolithography is the standard method of printed circuit board (PCB) and microprocessor fabrication. The process uses light to make the conductive paths of a PCB layer and the paths and electronic components in the silicon wafer of microprocessors.

The photolithography process involves light exposure through a mask to project the image of a circuit, much like a negative image in standard photography. This process hardens a photo-resistive layer on the PCB or wafer. The hardened areas stay behind in the form of circuit paths of PCBs and CPUs.  Unexposed areas are then dissolved away by a solution bath, such as an acid in wet methods or plasma-like oxygen ions in dry methods. A PCB might have as many as twelve of these layers and a processor might reach upwards of thirty, with some being metallic conductive layers and others insulating layers. Other steps include deposition of conductive metallic elements.

Process shrinks, also known as die shrinks, are one of the main ways that the miniaturization of electronic devices is made possible. Photolithography process shrinks involve miniaturization of all semiconductor devices, in particular transistors. Processors made on a smaller scale generally mean more CPUs per wafer, either for cheaper production or a more complex and powerful processor in a given die size. Progress in miniaturization also fosters faster transistor switching speeds and lower power consumption, so long as there is not too much current leakage (which is one of the challenges that increase with this progress).

Technology speculators have long predicted the end of photolithography as a viable method of making faster and cheaper processors. Since the 1980s, it has been thought it would not be possible to produce a structure smaller than one micrometer. As technology progresses, it requires shorter wavelengths of light and more tricks to focus down ever smaller. Due to the increasingly miniscule scale, a speck of dust can potentially ruin a processor. To safeguard the process, photolithography takes place in very clean rooms.  

Processors made in the 1970s through earlier methods used regular white light to produce processors on a scale of 10 micrometers.  Currently, they might use extreme ultra violet light for its smaller wavelength. The mask might be immersed in very pure deionized water, among other tricks, to enable the manufacturing of processors on a 22-nanometer scale with features that are actually smaller than the wavelength of light used. Current processors are so small they require a scanning electron microscope just to observe their structures.

See a video about photolithography:

 

This was last updated in August 2013

Continue Reading About photolithography

SearchCompliance

  • information governance

    Information governance is a holistic approach to managing corporate information by implementing processes, roles, controls and ...

  • enterprise document management (EDM)

    Enterprise document management (EDM) is a strategy for overseeing an organization's paper and electronic documents so they can be...

  • risk assessment

    Risk assessment is the identification of hazards that could negatively impact an organization's ability to conduct business.

SearchSecurity

  • PKI (public key infrastructure)

    PKI (public key infrastructure) is the underlying framework that enables entities -- users and servers -- to securely exchange ...

  • obfuscation

    Obfuscation means to make something difficult to understand.

  • dumpster diving

    Dumpster diving is looking for treasure in someone else's trash.

SearchHealthIT

SearchDisasterRecovery

  • risk mitigation

    Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a business.

  • call tree

    A call tree is a layered hierarchical communication model that is used to notify specific individuals of an event and coordinate ...

  • Disaster Recovery as a Service (DRaaS)

    Disaster recovery as a service (DRaaS) is the replication and hosting of physical or virtual servers by a third party to provide ...

SearchStorage

  • cloud storage

    Cloud storage is a service model in which data is transmitted and stored on remote storage systems, where it is maintained, ...

  • cloud testing

    Cloud testing is the process of using the cloud computing resources of a third-party service provider to test software ...

  • storage virtualization

    Storage virtualization is the pooling of physical storage from multiple storage devices into what appears to be a single storage ...

Close