INDEXING OF ELECTRONIC DEVICES WITH MULTIPLE WEIGHT MARKERS

• US 20150228589A1
• Filed: 04/20/2015
• Published: 08/13/2015
• Est. Priority Date: 10/09/2009
• Status: Active Grant

• Current Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Brenna, Emanuele, Di Franco, Antonio
• Granted Patent: US 10,643,950 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/82 to produce devices, e.g. integrated circuits, each consisting of a plurality of components
• CPC Class Codes: H01L 2223/54406 comprising alphanumeric information
• CPC Class Codes: H01L 2223/54413 comprising digital information, e.g. bar codes, data matrix
• CPC Class Codes: H01L 2223/5442 comprising non digital, non alphanumeric information, e.g. symbols
• CPC Class Codes: H01L 2223/54433 containing identification or tracking information
• CPC Class Codes: H01L 2223/5448 Located on chip prior to dicing and remaining on chip after dicing
• CPC Class Codes: H01L 23/544 Marks applied to semiconductor devices or parts, e.g. registration marks, alignment structures, wafer maps test patterns for characterising or monitoring manufacturing processes H01L22/00
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A die has a positional location in a wafer defined by first and second coordinates, the first and second coordinates identifying a respective horizontal and vertical location where the die was formed. An index formed on the die has a first comb structure of a first contiguous arrangement of first dots, and a second comb structure of a second contiguous arrangement of second dots. A first marker at a selected one of the first dots indicates a first digit of the first coordinate, and a first additional marker at a selected one of the first dots indicates a second digit of the first coordinate. A second marker at a selected one of the second dots indicates a first digit of the second coordinate, and a second additional marker at a selected one of the second dots indicates a second digit of the second coordinate.

Claims

1. An electronic device, comprising:

a die having a positional location in a wafer defined by first and second coordinates, wherein the first coordinate identifies a horizontal location where the die was formed, and wherein the second coordinate identifies a vertical location where the die was formed;

an index formed on the die, the index comprising;

a first comb structure comprising a first contiguous arrangement of first dots,

a second comb structure comprising a second contiguous arrangement of second dots,

a first marker at a selected one of the first dots, the first marker indicating a first digit of the first coordinate,

a first additional marker at a selected one of the first dots, the first additional marker indicating a second digit of the first coordinate,

a second marker at a selected one of the second dots, the second marker indicating a first digit of the second coordinate, and

a second additional marker at a selected one of the second dots, the second additional marker indicating a second digit of the second coordinate.

2. The electronic device of claim 1, wherein the first marker identifies teeth or spaces between teeth in the first comb structure;

and wherein the second marker identifies teeth or spaces between teeth in the second comb structure.

3. The electronic device of claim 1, wherein first dots and the second dots are arranged in a linear configuration.

4. The electronic device of claim 1, wherein the die has positional location in a shot location of the wafer defined by first and second shot coordinates, wherein the first shot coordinate identifies a horizontal location in the shot location where the die was formed, and wherein the second coordinate identifies a vertical location in the shot location where the die was formed.

5. The electronic device of claim 1, wherein the first digit of the first coordinate has a units weight and the second digit of the first coordinate has a tens weight;

and wherein the first digit of the second coordinate has a units weight and the second digit of the second coordinate has a tens weight.

6. The electronic device of claim 5, wherein a lack of the first marker or first additional marker indicates a null value of the first or second digit of the first coordinate, respectively;

and wherein a lack of the second marker or second additional marker indicates a null value of the first or second digit of the second coordinate, respectively.

7. The electronic device of claim 1, wherein the first and/or second comb structure includes an origin pad.

8. The electronic device of claim 1, wherein the first marker indicates an encrypted first digit of the first coordinate and wherein the first additional marker indicates an encrypted second digit of the first coordinate;

and wherein the second marker indicates an encrypted first digit of the second coordinate and wherein the second additional marker indicates an encrypted second digit of the second coordinate.

9. A method, comprising:

forming dice in a wafer, with each die having a positional location in the wafer defined by first and second coordinates, wherein the first coordinate identifies a horizontal location of the die in the wafer, and wherein the second coordinate identifies a vertical location of the die in the wafer; and

forming an index on each wafer by;

forming a first comb structure comprising a first contiguous arrangement of first dots on the wafer,

forming a second comb structure comprising a second contiguous arrangement of second dots on the wafer,

placing a first marker at a selected one of the first dots, the first marker indicating a first digit of the first coordinate,

placing a first additional marker at a selected one of the first dots, the first additional marker indicating a second digit of the first coordinate,

placing a second marker at a selected one of the second dots, the second marker indicating a first digit of the second coordinate, and

placing a second additional marker at a selected one of the second dots, the second additional marker indicating a second digit of the second coordinate.

10. The method of claim 9, wherein the first marker identifies teeth or spaces between teeth in the first comb structure;

and wherein the second marker identifies teeth or spaces between teeth in the second comb structure.

11. The method of claim 9, wherein first dots and the second dots are arranged in a linear configuration.

12. The method of claim 11, wherein the first digit of the first coordinate has a units weight and the second digit of the first coordinate has a tens weight;

and wherein the first digit of the second coordinate has a units weight and the second digit of the second coordinate has a tens weight.

13. The method of claim 12, wherein a lack of the first marker or first additional marker indicates a null value of the first or second digit of the first coordinate, respectively;

and wherein a lack of the second marker or second additional marker indicates a null value of the first or second digit of the second coordinate, respectively.

14. The method of claim 11, wherein the first and second comb structure each include an origin pad;

wherein the value of the first and second digits of the first coordinate is based on a distance from the origin pad of the first comb structure; and

wherein the value of the first and second digits of the second coordinate is based on a distance from the origin pas of the second comb structure.

15. A method for indexing electronic devices, comprising the steps of:

integrating a plurality of electronic circuits into portions of a wafer for corresponding dice;

forming at least one index on each die, each index including a reference defining an ordered alignment of a plurality of locations on the die and marker means for defining a value of the index according to an arrangement of the marker means with respect to the reference, the value of the index contributing to indicate a position of the die in the wafer; and

cutting the dice for forming electronic devices;

wherein the step of forming at least one index includes, for each index, forming a plurality of markers each one arranged at a selected one of the locations, the selected location of the marker defining a value of a digit associated with a corresponding power of a base higher than 2 within a number in a positional notation in said base representing the value of the index.

16. The method according to claim 15, wherein the ordered alignment of the locations is logically partitioned into a plurality of location subsets each one comprising of a plurality of consecutive locations for a corresponding marker, the step of forming at least one index on each die including forming each marker in a location of the corresponding location subset.

17. The method according to claim 15, wherein the step of forming at least one index on each die includes not forming the corresponding marker for defining a null value of each digit.

18. The method according to claim 15, wherein the step of forming at least one index on each die includes:

forming the reference of each index to include an origin indicator and a plurality of distance indicators extending along a straight line from the origin indicator, each distance indicator defining a corresponding location of the reference.

19. The method according to claim 18, wherein the step of forming the reference of each index includes:

forming the reference to include a comb-like structure having a spine and a plurality of teeth projecting from the spine, each portion of the spine between a pair of adjacent teeth defining a corresponding inter-tooth, each tooth and each inter-tooth identifying a corresponding location of the reference,

and wherein the step of forming a plurality of markers includes forming each marker to include of either a missing tooth or a missing inter-tooth.

20. The method according to claim 15, wherein the step of integrating a plurality of electronic circuits includes:

making a die subset comprising of a predetermined number of the dice concurrently in each one of a plurality of shot areas of the wafer, the die subsets being made in succession in the wafer, and

wherein the step of forming at least one index on each die includes setting the value of the at least one index to indicate a position of the die in the corresponding shot area.

21. The method according to claim 20, wherein the step of making a die subset includes:

arranging the dice of the die subset in a matrix having a plurality of rows and a plurality of columns;

and wherein the step of forming at least one index) on each die includes;

forming a row index and a column index, the row index being indicative of the row of the die in the matrix and the column index being indicative of the column of the die in the matrix.

22. The method according to claim 15, wherein the step of forming at least one index on each die includes encrypting the value of each index with an encryption key.