Periodic patterns and technique to control misalignment between two layers

• US 10,151,584 B2
• Filed: 10/30/2017
• Issued: 12/11/2018
• Est. Priority Date: 04/10/2001
• Status: Active Grant

• Current Assignee: KLA-Tencor Corporation
• Original Assignee: KLA-Tencor Corporation
• Inventors: Abdulhalim, Ibrahim, Adel, Mike, Friedmann, Michael, Faeyrman, Michael
• Primary Examiner(s): Rahman, Md M
• Application Number:
  US15/798,041
• Publication Number:
  US 20180100735A1
• Time in Patent Office: 407 Days
• Field of Search: 356399
• 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 target for measuring the relative positions between two layers of a device, the target comprising:

a first periodic structure in a first layer of the device; and

a second periodic structure having a first and second portion in a second layer of the device,

wherein the first portion of the second periodic structure overlies or interlaces with the first periodic structure and together are arranged so that the first portion of the second periodic structure is overlaid by the first periodic structure in a first region for measuring the relative positions between the first and second layers of the device,

wherein the second portion of the second periodic structure is in a second region for measuring a critical dimension of the second portion of the second periodic structure and the first periodic structure does not extend into such second region.

2. The target of claim 1, wherein the first and second periodic structure are periodic in a first direction, and the second periodic structure extends in a direction that is different from the first direction into the region where the two structures do not overlap and where the first periodic structure does not extend.

3. The target of claim 1, wherein a plurality of lines of the first periodic structure and a plurality of lines of the first portion of the second periodic structure overlay each other.

4. The target of claim 1, wherein a plurality of lines of the first periodic structure and a plurality of lines of the first portion of the second periodic structure are interlaced with each other.

5. A target for measuring the relative positions between two layers of a device, the target comprising:

a first periodic structure in a first layer of the device; and

a second periodic structure in a second layer overlying or interlacing with-the first periodic structure, wherein a first region includes a first portion of the second periodic structure overlaid by the first periodic structure and arranged for measuring the relative positions between the first and second layers of the device,

wherein the first or second periodic structure has at least two periodic gratings that are interlaced and have different critical dimensions, and

wherein a second region includes a second portion of the second periodic structure for measuring the different critical dimensions of such second portion and in which the first periodic structure is not present.

6. The target of claim 5, wherein the at least two periodic gratings having different duty cycles.

7. The target of claim 5, wherein the at least two periodic gratings having different line widths.

8. The target of claim 5, wherein a plurality of lines of the first periodic structure and a plurality of lines of the first portion the second periodic structure overlay each other.

9. The target of claim 5, wherein a plurality of lines of the first periodic structure and a plurality of lines of the first portion of the second periodic structure are interlaced with each other.