DEVICE-SPECIFIC MARKINGS
Producing a plurality of electronic devices by a technique including photolithographically patterning a layer of conductive material ( 3 ), and defining at least one device-specific mark ( 3 a ) of a respective one of the plurality of devices as part of photolithographically patterning said layer of conductive material.
1 . A method, comprising: producing a plurality of electronic devices by a technique including photolithographically patterning a layer of material, and defining at least one device-specific mark of a respective one of the plurality of devices as part of photolithographically patterning said layer of material.
2 . A method according to claim 1 , comprising defining the at least one device-specific mark in said layer of material simultaneously to defining in said layer of material a pattern common to the plurality of devices.
3 . A method comprising: producing a plurality of electronic devices by a technique including patterning a layer of material, wherein the method comprises defining in said layer of material at least one device-specific mark of a respective one of the plurality of devices simultaneously to defining in said layer of material a pattern common to the plurality of devices.
4 . A method according to claim 3 , wherein said pattern common to the plurality of devices defines an array of electronically functional elements.
5 . A method according to claim 4 , wherein said array of electronically functional elements comprises an array of electrodes for an array of transistors.
6 . A method according to claim 3 , wherein defining said pattern common to the plurality of devices comprises a first exposure technique by which a mask is used to expose to radiation selected first regions of a photosensitive layer on said layer of material; and wherein defining said device-specific mark comprises a second exposure technique by which selected second regions not exposed to radiation by said first technique are exposed to radiation.
7 . A method according to claim 6 , wherein exposing said first and second selected regions to radiation changes the solubility of the photosensitive layer in said regions, and further comprising treating the photosensitive layer with a solvent to selectively remove said photosensitive layer in either said first and second selected regions or to selectively remove said photosensitive layer in all unexposed regions; and then using the thus patterned photosensitive layer as a mask to pattern the underlying said layer of material and simultaneously define said common pattern and said device-specific marking in said layer of material.
8 . A method according to claim 6 , comprising performing said first exposure technique before said second exposure technique.
9 . A method according to claim 6 , comprising performing said second exposure technique before said first exposure technique.
10 . A method according to claim 6 , comprising performing said second exposure technique using a laser beam writer.
11 . A method according to claim 1 , wherein said device-specific mark is one or more selected from the group consisting of a barcode, a matrix code, numerals and text.
12 . A method according to claim 1 , wherein said layer of material is a layer of conductive material.
13 . A method according to claim 3 , wherein said device-specific mark is one or more selected from the group consisting of a barcode, a matrix code, numerals and text.
14 . A method according to claim 1 , wherein said layer of material is a layer of conductive material.
15 . A method according to claim 7 , comprising performing said second exposure technique before said first exposure technique.