Claims
- 1. A method for storing information in a semiconductor structure, comprising:forming a layer of conductive material on a substrate; and during said forming of said layer, forming in said layer a read-only storage element and programming said read-only storage element to a state representative of information identifying a mask used in forming the read-only storage element.
- 2. The method of claim 1, further comprising after said forming and programming said read-only storage element reading said read-only storage element.
- 3. A method for forming an integrated circuit, comprising:forming on a substrate a plurality of conductive layers; during the forming of a first of said layers, forming in said first of said layers a first portion of a storage element; and during the forming of a second of said layers, forming in said second of said layers a second portion of said storage element; and electrically connecting said second portion to said first portion to store mask information identifying a mask used to form either the first or second layers.
- 4. The method of claim 3 wherein said connecting comprises serially connecting said first portion to said second portion.
- 5. The method of claim 3, further comprising forming said storage element having more than two portions, no more than one of said portions formed in each of said conductive layers.
- 6. A method for encoding identification data on a semiconductor device, comprising:forming on a substrate a first plurality of conductive layers; and forming in one or more of said conductive layers a storage module that is encoded with data identifying a mask set used to form the semiconductor device, said module including a second plurality of electrically and parallel coupled storage elements, each of said storage elements including multiple electrically and serially intercoupled storage links.
- 7. The method of claim 6, further comprising:forming each of said storage links of each of said storage elements in a different one of said conductive layers; and changing a conductivity of one or more of said storage links in only one layer to change said data.
- 8. The method of claim 6, further comprising reading said data from said storage module.
- 9. The method of claim 6 wherein said forming said storage module comprises:forming one of said storage elements in a conducting state; and forming remaining ones of said storage elements in a nonconducting state by forming one nonconducting storage link in each of said remaining storage elements, each nonconducting storage link formed in a different one of said layers such that each layer contains a nonconducting storage link from at most one of said storage elements.
- 10. The method of claim 6 wherein said forming said storage module comprises forming each of said storage elements in a nonconducting state by forming one nonconducting storage link in each of said storage elements, each nonconducting storage link formed in a different one of said layers such that each layer contains a nonconducting storage link from no more than one of said storage elements.
- 11. A method for forming a semiconductor structure, comprising:forming a conductive layer on a substrate using a mask; forming in said conductive layer one or more read-only storage elements each having a predetermined digital state, said predetermined digital states of said storage elements together identifying said mask.
- 12. The method of claim 11, further comprising:forming each of a plurality of conductive layers on said substrate using a mask that is different from masks used to form other of said conductive layers; and forming in said each conductive layer one or more read-only storage elements each having a predetermined digital state, said predetermined digital states of said storage elements in said each conductive layer together identifying said mask used to form said each conductive layer.
- 13. A method for forming an integrated device, comprising:forming on a substrate a plurality of conductive layers; and forming in each conductive layer one or more read-only storage elements that permanently store a desired data value pertaining to said each conductive layer.
- 14. The method of claim 13 wherein said forming in each conductive layer comprises forming said one or more read-only storage elements to permanently store in digital form a version number of a mask used to form said each conductive layer.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a division of U.S. patent application Ser. No. 08/664,109, filed Jun. 13, 1996 now U.S. Pat. No. 5,895,962.
US Referenced Citations (9)