The arrangement on a chip of semiconductor devices such as transistors and passive electronic components such as resistors and interconnections. A mask work is a two or three-dimensional layout of an integrated circuit.
A mask work also refers to the intellectual property right conferring time-limited exclusivity to reproduction of a particular layout. The layout is called a mask work because, in photolithographic processes, the multiple etched layers within actual ICs are each created using a mask, called the photomask, to permit or block the light at specific locations, sometimes for hundreds of chips on a wafer simultaneously.
Because of the functional nature of the mask geometry, the designs cannot be effectively protected under copyright law (except perhaps as decorative art). Similarly, because individual lithographic mask works are not clearly protectable subject matter, they also cannot be effectively protected under patent law, although their combined functions and structure certainly may.
The United States Code (USC) defines a mask work as a series of related images, however fixed or encoded, having or representing the predetermined, three-dimensional pattern of metallic, insulating, or semiconductor material present or removed from the layers of a semiconductor chip product, and in which the relation of the images to one another is such that each image has the pattern of the surface of one form of the semiconductor chip product. (17 USC § 901 (a) (2)).
Mask work exclusive rights were first granted in the US
by the Semiconductor Chip Protection Act of 1984. In Canada these rights are protected
under the Integrated Circuit Topography Act (1990, c. 37). Equivalent legislation exists
in Australia and Hong Kong.
Mask work rights under US Law
According to 17 USC § 904, rights in semiconductor mask work last only two years (if unregistered) or ten years (if registered). Contrast this with the effectively perpetual terms for modern copyrighted works and the fact that mask works are not subject to any statutory fair use defense, nor the typical backup copy exemptions that 17 USC § 117 provides for computer software. Nevertheless, as fair use in copyrighted works was originally recognized by the judiciary long before being codified in statute, it may one day be recognized in mask work protection as well.
Mask works, copyrights, and read-only memory
The exclusive rights in a mask work are somewhat like those of copyright: the right to reproduce the mask work or (initially) distribute an IC made using the mask work. Like the first sale doctrine, a lawful owner of an authorized IC containing a mask work may freely import, distribute or use, but not reproduce the chip (or the mask). Mask work protection is characterized as a sui generis right, i.e., one created to protect specific rights where other (more general) laws were inadequate or inappropriate.
The exclusive rights granted to mask work owners are more limited than those granted to copyright or patent holders. For instance, modification (derivative works) is not an exclusive right of mask work owners. Similarly, the exclusive right of a patentee to use an invention would not prohibit an independently created mask work of identical geometry. Furthermore, reproduction for reverse engineering of a mask work is specifically permitted by the law. As with copyright, mask work rights exist when they are created, regardless of registration, unlike patents, which only confer rights after application, examination and issuance.
Mask work rights have more in common with copyrights than with other exclusive rights such as patents or trademarks. On the other hand, they are used alongside copyright to protect a read-only memory (ROM) component that is encoded to contain computer software.
The publisher of software for a cartridge-based video game console may seek simultaneous protection of its property under several legal constructs:
a Form MW mask work registration on the ROM that contains
The expiration date for the term of mask work may be set according to an untested interpretation of the originality requirement of § 902(b), based on the release of the console, not any particular cartridge.
(b) Protection under this chapter (i.e., as a mask work) shall not be available for a mask work that -
is not original; or
consists of designs that are staple, commonplace, or familiar in the semiconductor industry, or variations of such designs, combined in a way that, considered as a whole, is not original (17 USC § 902, US Code at Cornell, as of February 2003).
Under this interpretation, a mask work containing a given game title is either entirely unoriginal, as mask ROM in general is likely a familiar design, or a minor variation of the mask work for any of the first titles released for the console in the region, normally the cartridge included with the system.