Periodic patterns and techniques to control misalignment between two layers

• US 9,234,745 B2
• Filed: 07/01/2015
• Issued: 01/12/2016
• Est. Priority Date: 04/10/2001
• Status: Expired due to Fees

• Current Assignee: KLA-Tencor Corporation (KLA Corporation)
• Original Assignee: KLA-Tencor Corporation (KLA Corporation)
• Inventors: Abdulhalim, Ibrahim, Adel, Mike, Friedmann, Michael, Faeyrman, Michael
• Primary Examiner(s): Chowdhury, Tarifur
• Assistant Examiner(s): RAHMAN, MD M
• Application Number:
  US14/789,796
• Publication Number:
  US 20150300815A1
• Time in Patent Office: 195 Days
• Field of Search: 356/399
• US Class Current: 1/1
• CPC Class Codes: G01B 11/14 for measuring distance or clearance between spaced objects or spaced apertures G01B11/26 takes precedence; rangefinders G01C3/00
• CPC Class Codes: G01B 11/26 for measuring angles or tapers; for testing the alignment of axes
• CPC Class Codes: G01N 21/9501 Semiconductor wafers manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G03F 7/70633 Overlay, i.e. relative alignment between patterns printed by separate exposures in different layers, or in the same layer in multiple exposures or stitching
• CPC Class Codes: H01L 22/12 for structural parameters, e.g. thickness, line width, refractive index, temperature, warp, bond strength, defects, optical inspection, electrical measurement of structural dimensions, metallurgic measurement of diffusions electrical measurement of diffusions H01L22/14
• CPC Class Codes: H01L 2223/54426 for alignment
• CPC Class Codes: H01L 2223/54453 for use prior to dicing
• CPC Class Codes: H01L 2223/5446 Located in scribe lines
• 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 method and system to measure misalignment error between two overlying or interlaced periodic structures are proposed. The overlying or interlaced periodic structures are illuminated by incident radiation, and the diffracted radiation of the incident radiation by the overlying or interlaced periodic structures are detected to provide an output signal. The misalignment between the overlying or interlaced periodic structures may then be determined from the output signal.

Claims

1. A method for processing and measuring a device, said device having a first periodic structure, said method comprising:

measuring a critical dimension of the first periodic structure by illuminating the first periodic structure with incident electromagnetic radiation and by detecting diffracted electromagnetic radiation from the illuminated portions of the first periodic structure;

after the first periodic structure has been measured, forming a second periodic structure in a region of the device, where the first and second periodic structures are present in said region; and

measuring a relative position between the first and second periodic structures by illuminating the first and second periodic structures with incident electromagnetic radiation and by detecting diffracted electromagnetic radiation from the illuminated portions of the first and second periodic structures in said region, wherein said measuring of the relative position between the first and second periodic structures includes detecting positive and negative first order diffracted electromagnetic radiation from the illuminated portions of the first and second periodic structures in said region, and deriving differential intensity between the positive and negative first-order diffraction, differential phase between the positive and negative first-order diffraction or differential polarization between the positive and negative first-order diffraction.

2. The method of claim 1, wherein the second periodic structure is formed so that the first and second periodic structures overlie one another in the region.

3. The method of claim 1, wherein a width of the first periodic structure is measured.

4. The method of claim 1, further comprising measuring the second periodic structure.

5. The method of claim 4, wherein said second periodic structure includes a first and a second portion, wherein the first portion is in the region where the first periodic structure is present and the second portion is in a second region where the first periodic structure is not present, and the second periodic structure is measured by measuring said second portion of said second periodic structure in the second region.

6. The method of claim 4, wherein the second periodic structure is measured by illuminating the second periodic structure with incident electromagnetic radiation and by detecting diffracted electromagnetic radiation from the illuminated portions of the second periodic structure.

7. The method of claim 1, wherein measuring the relative position between the first and second periodic structures determines a misalignment between a first and a second layer that were formed respectively together with the first and second periodic structures.

8. The method of claim 1, wherein a first portion of said second periodic structure is in the region, and the measuring of the relative position between the first and second periodic structures is made by illuminating the first and second periodic structures in the region with incident electromagnetic radiation and by detecting diffracted electromagnetic radiation from the first and second periodic structures in said region.

9. The method of claim 8, wherein a second portion of said second periodic structure different from the first portion is in a second region where the first periodic structure is not present.

10. A method for measuring a relative position between a first and a second layer of a device, a first periodic structure having been formed with the first layer of the device and a second periodic structure having been formed with the second layer of the device, said second periodic structure overlying or interlaced with said first periodic structure, said method comprising:

measuring a critical dimension of at least one of the first and second periodic structures in a first region where the at least one periodic structure is present and the other periodic structure is not present, said measuring including detecting a diffraction of electromagnetic radiation from the periodic structure that is measured, wherein measurement of at least one of the first and second periodic structures is performed without measuring the other one of the first and second periodic structures; and

measuring a relative position between the first and second layers in a second region different from the first region, where the first and second periodic structures are present in said second region, wherein said measuring of the relative position includes determining a misalignment between the first and second periodic structures,

said measuring of the critical dimension including detecting the zeroth or the first order diffraction from the first or second periodic structure.

11. The method of claim 10, wherein a width of the first or second periodic structure is measured.

12. The method of claim 10, wherein said determining determines the misalignment between the first and second periodic structures from a diffraction from the first and second periodic structures.