Method and apparatus for obtaining two- or three-dimensional information from scanning electron microscopy

• US 6,054,710 A
• Filed: 12/18/1997
• Issued: 04/25/2000
• Est. Priority Date: 12/18/1997
• Status: Expired due to Term

• Current Assignee: Monterey Research, LLC (Vector Capital Corporation)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Bruggeman, Albert C.
• Primary Examiner(s): BERMAN, JACK I
• Application Number:
  US08/993,036
• Time in Patent Office: 859 Days
• Field of Search: 250/307, 250/252.1 R
• US Class Current: 250/307
• CPC Class Codes: G03F 7/70491 Information management, e.g. software; Active and passive control, e.g. details of controlling exposure processes or exposure tool monitoring processes
• CPC Class Codes: G03F 7/705 Modelling or simulating from physical phenomena up to complete wafer processes or whole workflow in wafer productions
• CPC Class Codes: G03F 7/70625 Dimensions, e.g. line width, critical dimension [CD], profile, sidewall angle or edge roughness
• CPC Class Codes: Y10S 977/854 Semiconductor sample

Abstract

A system for determining one or more critical dimension(s) of a semiconductor structure comprising a scanning electron microscope and a parallel distributed process operationally connected to an output of a scanning electron microscope. Said parallel distributed process containing coefficients that provide a multi dimensional mapping space for the output of said scanning electron microscope to map to an output value that provides information on the dimensions of the semiconductor structure.

Claims

1. A system for determining one or more critical dimension(s) of a semiconductor structure comprising:

a scanning electron microscope;

a parallel distributed process operationally connected to an output of the scanning electron microscope, said parallel distributed process containing coefficients that provide a multi dimensional mapping space for the output of said scanning electron microscope to map to an output value that provides information on the critical dimension of the semiconductor structure.

2. The system of claim 1 wherein said parallel distributed process comprises a feed-forward artificial neural network.

3. The system of claim 1 wherein said coefficients that provide said multidimensional mapping space are determined by measuring dimensions of a similar or identically prepared semiconductor structure with an atomic force microscope.

4. The system of claim 1 wherein said coefficients are on a storage device.

6. The system of claim 1, wherein said critical dimension(s) is/are multidimensional.

5. A method for determining the three dimensional characteristics of a semiconductor structure from a two dimensional waveform, comprising the steps of:

providing a two dimensional waveform of a semiconductor structure from a first measurement instrument;

mapping said two dimensional waveform through a multi-dimensional decision space to a corresponding three dimensional characteristic.

7. The method of claim 5 comprising the further step of:

providing a network configuration and network weights to define said multidimensional decision space.

8. The method of claim 5 comprising the further step of:

determining said corresponding three dimensional characteristics from a second measurement instrument.

9. The method of claim 5 wherein said first measurement instrument is a scanning electron microscope.

10. The method of claim 8 wherein said second measurement instrument is an atomic force microscope.

11. A method for determining the critical dimension of a semiconductor structure with a scanning electron microscope comprising the steps of:

collecting a first measurement of a first semiconductor structure from a scanning electron microscope;

collecting a second measurement of said first semiconductor structure from an atomic force microscope;

establishing a relationship between said first measurement and said second measurement of said first semiconductor structure wherein said relationship indicates said second measurement if a third measurement from a scanning electron microscope of a second semiconductor structure has characteristics similar to said first semiconductor structure; and

mapping a two dimensional waveform through a multi-dimensional decision space to a corresponding three dimensional characteristic using a parallel distributed process operationally connected to an output of said scanning electron microscope, said parallel distributed process containing coefficients that provide said multi-dimensional mapping space for the out put of said scanning electron microscope to map to an output value that provides information on the critical dimension of the semiconductor structure.