Physically unclonable product and fabrication method thereof

Patent metadata

Field	Value
Publication number	US-9876498-B2
Application number	US-201615332866-A
Country	US
Kind code	B2
Filing date	Oct 24, 2016
Priority date	Dec 1, 2015
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

The present disclosure provides physically unclonable products and fabrication methods thereof. An exemplary fabrication method forming a resistor block; performing a resistance randomizing process to the resistor block to cause the resistor block to have a random resistance; forming a resistor block array using at least two resistor blocks obtained after the resistance randomizing process; and coupling at least one resistor block array with a product to form the physically unclonable product.

First claim

What is claimed is:

1. A method for fabricating a physically unclonable product, comprising:
forming a resistor block;
performing a resistance randomizing process to the resistor block to cause the resistor block to have a random resistance;
forming a resistor block array using at least two resistor blocks obtained after the resistance randomizing process; and
coupling at least one resistor block array with a product to form the physically unclonable product.

2. The method according to claim 1 , wherein:
the at least two resistor blocks obtained after the resistance randomizing process include a first resistor block and a second resistor block;
an output of the resistor block array is “1”, when a resistance of the first resistor block is greater than a resistance of the second resistor block; and
an output of the resistor block array is “0”, when the resistance of the first resistor block is smaller than a resistance of the second resistor block.

3. The method according to claim 1 , wherein performing the resistance randomizing process comprises:
performing a photoresist treatment process to the resistor block by performing an adjustment operation to cause an energy of the photoresist treatment process to be unable to completely expose positions of a photoresist layer on the resistor block corresponding to need-to-be-exposed regions in a photomask.

4. The method according to claim 3 , wherein the adjustment operation includes at least one of:
adjusting an energy for exposing the photoresist layer on the resistor block; and
adjusting sizes of the need-to-be-exposed regions in the photomask.

5. The method according to claim 1 , wherein the resistor block comprises:
at least two resistor block units,
wherein:
the at least two resistor block units are parallel; and
the at least two resistor block units are separated by a space.

6. The method according to claim 5 , wherein performing the resistance randomizing process comprises:
performing an adjustment operation to cause the energy of the photoresist adjustment process to be unable to completely expose portions of a photoresist layer between two resistor block units corresponding to need-to-be-exposed regions on the photomask.

7. The method according to claim 6 , wherein the adjustment operation comprises at least one of:
adjusting an energy for performing the photoresist treatment on the resistor block; and
adjusting sizes of the need-to-be exposed regions on the photomask.

8. The method according to claim 1 , wherein the resistor block comprises:
at least two long-stripe resistor block units,
wherein:
the at least two long-stripe resistor block units connect to each other; and
a width of one long-stripe resistor block unit is greater than a width of another long-stripe resistor block unit.

9. The method according to claim 8 , wherein performing the resistance randomizing process comprises:
performing an adjustment operation to cause one of the long-stripe resistor block units to be bridged and another long-stripe resistor block unit to be broken.

10. The method according to claim 9 , wherein the adjustment operation comprises at least one of:
adjusting an energy of the photoresist treatment process to the resistor block; and
adjusting a relative width between the long-stripe resistor block units.

11. The method according to claim 1 , wherein the resistance randomizing process comprises:
doping the resistor block to cause doped regions in the resistor block to have a higher etching rate than un-doped regions in the resistor block; and
etching the doped resistor block and adjusting etching parameters to cause the resistor block to have different critical dimensions at different positions.

12. The method according to claim 11 , wherein:
a critical dimension of a top of the resistor block is smaller than a critical dimension of a bottom of the resistor block.

13. The method according to claim 1 , wherein:
the resistor block is made of one of polysilicon and metal material.

14. A physically unclonable product, comprising:
a product; and
at least one resistor block array coupled with the product and including at least two resistor blocks having randomized resistances, wherein:
the at least two resistor blocks include a first resistor block and a second resistor block;
an output of the resistor block array is “1”, when a resistance of the first resistor block is greater than a resistance the second resistor block; and
an output of the resistor block array is “ 0 ”, when the resistance of the first resistor block is greater than the resistance of the second resistor block.

15. The physically unclonable product according to claim 14 , wherein the resistor block comprises:
at least two resistor block units,
wherein:
the at least two resistor block units are parallel to each other; and
the at least two resistor block units are separated by a space.

16. The physically unclonable product according to claim 14 , wherein the resistor block comprises:
at least two long-stripe resistor block units,
wherein
the at least two long-stripe resistor block units connect to each other; and
a width of one long-stripe resistor block unit is greater than a width of another long-stripe resistor block.

17. The physically unclonable product according to claim 14 , wherein:
a critical dimension of a top of the resistor block is smaller than a critical dimension of a bottom of the resistor block.

18. The physically unclonable product according to claim 14 , wherein:
the resistor block is a conductive plate having an electrical resistance.

19. The physically unclonable product according to claim 14 , wherein the product comprises one of:
an intelligent card, a radio frequency identification card, and a storage device.

Assignees

• Semiconductor Mfg International (Beijing) Corporation
• Semiconductor Mfg International (Shanghai) Corporation

Inventors

• Zhao Lian Guo
• Peng Kun
• Hu Xiang
• Wang Hai Lian

Classifications

• H10W42/405

  using active circuits · CPC title

• H01L23/576

  Electricity · mapped topic

• H03K19/0005 Primary

  Modifications of input or output impedance · CPC title

• H03K19/003

  Modifications for increasing the reliability {for protection} · CPC title

• H04L2209/12

  Details relating to cryptographic hardware or logic circuitry · CPC title