Indexing of electronic devices with multiple weight markers

• US 10,643,950 B2
• Filed: 04/20/2015
• Issued: 05/05/2020
• 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
• Primary Examiner(s): Harrison, Monica D
• Application Number:
  US14/691,200
• Publication Number:
  US 20150228589A1
• Time in Patent Office: 1,842 Days
• Field of Search: 257 40
• 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 shot defined by first and second die coordinates, wherein the shot has a positional location in a wafer defined by first and second shot coordinates, wherein the first die coordinate identifies a horizontal location in the shot where the die was formed, wherein the second die coordinate identifies a vertical location in the shot where the die was formed, wherein the first shot coordinate identifies a horizontal location on the wafer where the shot resides, wherein the second shot coordinate identifies a vertical location on the wafer where the shot resides;

a first comb structure comprising a first spine with a first plurality of teeth projecting transversally therefrom, and wherein portions of the first spine between pairs of adjacent teeth of the first plurality of teeth define first inter-tooth portions, the first plurality of teeth and first inter-tooth portions defining a first contiguous arrangement of first dots,

a second comb structure comprising a second spine with a second plurality of teeth projecting transversally therefrom, and wherein portions of the second spine between pairs of adjacent teeth of the second plurality of teeth define second inter-tooth portions, the second plurality of teeth and second inter-tooth portions defining 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 a two digit number for the first die coordinate,

a first additional marker at a selected one of the first dots, the first additional marker indicating a second digit of the two digit number for the first die coordinate,

a second marker at a selected one of the second dots, the second marker indicating a first digit of a two digit number for the second die coordinate, and

a second additional marker at a selected one of the second dots, the second additional marker indicating a second digit of the two digit number for the second die coordinate.

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

3. The electronic device of claim 1, wherein the first digit of the first die coordinate has a units weight for the two digit number and the second digit of the first die coordinate has a tens weight for the two digit number;

and wherein the first digit of the second die coordinate has a units weight for the two digit number and the second digit of the second die coordinate has a tens weight for the two digit number.

4. The electronic device of claim 3, wherein a lack of the first marker or first additional marker indicates a null or zero value of the first or second digit of the first die coordinate, respectively;

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

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

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

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

7. The electronic device of claim 1, further comprising:

a third comb structure comprising a third spine with a third plurality of teeth projecting transversally therefrom, and wherein portions of the third spine between pairs of adjacent teeth of the third plurality of teeth define third inter-tooth portions, the third plurality of teeth and the third inter-tooth portions defining a third contiguous arrangement of third dots,

a first separation pad connecting the first and third spines;

a fourth comb structure comprising a fourth spine with a fourth plurality of teeth projecting transversally therefrom, and wherein portions of the third spine between pairs of adjacent teeth of the fourth plurality of teeth define fourth inter-tooth portions, the fourth plurality of teeth and the fourth inter-tooth portions defining a fourth contiguous arrangement of fourth dots;

a second separation pad connecting the second and fourth spines;

a third marker at a selected one of the third dots, the third marker indicating a digit number of the first shot coordinate; and

a fourth marker at a selected one of the fourth dots, the fourth marker indicating a digit number of the second shot coordinate.

8. A method, comprising:

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

forming a first comb structure on each die and comprising a first spine with a first plurality of teeth projecting transversally therefrom, and wherein portions of the first spine between pairs of adjacent teeth of the first plurality of teeth define first inter-tooth portions, the first plurality of teeth and first inter-tooth portions defining a first contiguous arrangement of first dots at each die location on the wafer,

forming a second comb structure on each die and comprising a second spine with a second plurality of teeth projecting transversally therefrom, and wherein portions of the second spine between pairs of adjacent teeth of the second plurality of teeth define second inter-tooth portions, the second plurality of teeth and second inter-tooth portions defining 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 a two digit number for the first die coordinate,

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

placing a second marker at a selected one of the second dots, the second marker indicating a first digit of a two digit number for the second die 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 two digit number for the second die coordinate.

9. The method of claim 8, wherein first dots and the second dots are arranged in a linear configuration.

10. The method of claim 9, wherein the first digit of the first die coordinate has a units weight for the two digit number and the second digit of the first die coordinate has a tens weight for the two digit number;

and wherein the first digit of the second die coordinate has a units weight for the two digit number and the second digit of the second die coordinate has a tens weight for the two digit number.

11. The method of claim 10, wherein a lack of the first marker or first additional marker indicates a null or zero value of the first or second digit of the first die coordinate, respectively;

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

12. The method of claim 9, wherein the first and second comb structure each include an origin pad;

wherein a value of the first die coordinate is based on a distance of the first marker and first additional marker from the origin pad of the first comb structure; and

wherein the value of the second die coordinate and second shot coordinate is based on a distance of the second marker and second additional marker from the origin pad of the second comb structure.

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

integrating a plurality of electronic circuits into portions of a wafer for corresponding dice, each die having a specific die location in the wafer;

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 die location according to an arrangement of the marker means with respect to the reference, the value of the index indicating the specific die location 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.

14. The method according to claim 13, 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 a corresponding location subset.

15. The method according to claim 13, wherein the step of forming at least one index on each die includes not forming a corresponding marker for defining a null value of each digit.

16. The method according to claim 13, wherein the step of forming at least one index on each die includes:

forming a 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.

17. The method according to claim 16, wherein the step of forming a 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.

18. The method according to claim 13, 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 die location of the die in the corresponding shot area.

19. The method according to claim 18,

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.

20. The method according to claim 13, wherein the step of forming at least one index on each die includes encrypting a value of each index with an encryption key.

21. An electronic device, comprising:

a die having a positional location within a shot defined by first and second two digit die coordinate values, wherein the first two digit die coordinate value identifies a horizontal location within the shot where the die was formed, and wherein the second two digit die coordinate value identifies a vertical location within the shot where the die was formed; and

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 first selected one of the first dots, the first marker specifying a first digit of the first two digit die coordinate value,

a second marker at a second selected one of the first dots, the second marker specifying a second digit of the first two digit die coordinate value,

a third marker at a first selected one of the second dots, the third marker specifying a first digit of the second two digit die coordinate value, and

a fourth marker at a second selected one of the second dots, the fourth marker specifying a second digit of the second two digit die coordinate value.

22. The electronic device of claim 21, wherein the first dots are located at teeth or spaces between teeth in the first comb structure;

and wherein the second dots are located at teeth or spaces between teeth in the second comb structure.

23. The electronic device of claim 21, wherein each first digit specifies a units weight for the two digit die coordinate value and each second digit specifies a tens weight for the two digit die coordinate value.

24. The electronic device of claim 21, wherein absence of one of the first through fourth markers indicates a null value of the corresponding first or second digit.