Side alignment mark

DETAILED DESCRIPTION This invention overcomes the above-noted disadvantages.
An apparatus in accordance with this invention includes an alignment mark that is formed in a substrate.
The mark extends across a dice line so that, upon dicing the substrate, the mark is exposed in the substrate's side edge.
The mark is formed at a predetermined distance from a position at which a feature is desired to be formed on the substrate's side edge using a mask.
Accordingly, the mark is a positional reference that can be used for highly accurate placement of the feature with the mask.
Preferably, the mark is formed of metal or other material with an enhanced size and appearance that are readily detectable by an alignment system with which the mark is to be used.
In a preferred configuration, the mark is formed with the same mask as that used to form a specific component of an integrated device in relation to which it is desired to form the feature.
For example, the component can be the contact layers for the read gap of a thin-film head.
The invented alignment mark is positioned at a predetermined distance from the component as determined by the mask.
Like the mark, the integrated device is formed in the substrate and exposed in the substrate's side edge upon dicing and polishing the substrate.
Preferably, the mark is formed together with the component at a relatively early step in the manufacture of the integrated device so that the mark's position is relatively unaffected by successive misalignments that generally occur over later steps in the integrated device's formation.
The invented alignment mark can be used as a positional reference for a mask to form a variety of different kinds of features.
For example, the aligned mask can be used to pattern a resist layer to expose two window portions on opposite sides of a write gap bridge for a thin-film head device.
Portions of the substrate and integrated device that are exposed by the windows, are removed by ion milling or reactive ion etching, for example