Method for placing fluorescent single molecules on surface of substrate and method for visualizing structural defect of surface of substrate

• US 5,965,446 A
• Filed: 10/24/1997
• Issued: 10/12/1999
• Est. Priority Date: 10/24/1996
• Status: Expired due to Fees

• Current Assignee: Hamamatsu Photonics KK
• Original Assignee: Hamamatsu Photonics KK
• Inventors: Ishikawa, Mitsuru
• Primary Examiner(s): Warden, Jill
• Assistant Examiner(s): Cannell, Kevin P.
• Application Number:
  US08/957,360
• Time in Patent Office: 718 Days
• Field of Search: 436/5, 436/172, 356/237.1, 356/237.5, 427/157, 427/355
• US Class Current: 436/5
• CPC Class Codes: B05D 1/28 performed by transfer from the surfaces of elements carrying the liquid or other fluent material, e.g. brushes, pads, rollers
• CPC Class Codes: H01L 22/24 Optical enhancement of defects or not directly visible states, e.g. selective electrolytic deposition, bubbles in liquids, light emission, colour change voltage contrast G01R31/311

Abstract

A method for placing fluorescent single molecules on a surface of a substrate includes dropping a sample solution in which fluorescent molecules are dissolved in a predetermined concentration in a volatile, organic solvent, onto a slip of paper placed on the substrate and pulling the slip of paper so as to make the dropped sample solution traverse the surface of the substrate before the organic solvent evaporates. Since a single molecular layer of fluorescent molecules with high uniformity can be placed readily on the surface of the substrate, measurement of fluorescence and measurement of scattered light can be carried out accurately and structural defects of the surface of substrate can be visualized from luminous spots of fluorescence and from luminous spots of scattered light.

Claims

1. A method for placing fluorescent single molecules on a surface of a substrate, on the occasion of carrying out measurement of fluorescence of fluorescent molecules, comprising the steps of:

dissolving said fluorescent molecules in a predetermined concentration in a volatile, organic solvent, thereby preparing a sample solution;

placing a slip of paper on a substrate where the measurement of fluorescence is carried out;

dropping said sample solution onto said slip of paper placed on said substrate; and

then pulling said slip of paper so as to make the dropped sample solution traverse said surface of the substrate before said organic solvent evaporates thereby placing the fluorescent single molecules on the surface of the substrate, wherein the fluorescent single molecules are distinguishable on the surface of the substrate.

2. A method for placing fluorescent single molecules on a surface of a substrate, according to claim 1, wherein said organic solvent is one selected from the group consisting of alcohols, ethers, and acetone.

3. A method for placing fluorescent single molecules on a surface of a substrate, according to claim 1, wherein said slip of paper is a slip of paper selected from the group consisting of lens cleaning paper, carbon base paper, and thin paper.

4. A method for placing fluorescent single molecules on a surface of a substrate, according to claim 1, wherein the concentration of said fluorescent molecules is 10^-4 M or less.

5. A method for visualizing a structural defect of a surface of a substrate, on the occasion of carrying out measurement of fluorescence of fluorescent molecules, comprising the steps of:

dissolving said fluorescent molecules in a predetermined concentration in a volatile, organic solvent, thereby preparing a sample solution;

placing a slip of paper on a substrate where the measurement of fluorescence is carried out;

dropping said sample solution onto said slip of paper placed on said substrate;

pulling said slip of paper so as to make the dropped sample solution traverse said surface of the substrate before said organic solvent evaporates, thereby placing the fluorescent single molecules on the surface of the substrate wherein the fluorescent single molecules are distinguishable on the surface of the substrate;

radiating laser light to the surface of said substrate on which said fluorescent single molecules are placed;

then measuring fluorescence generated in said surface of the substrate; and

obtaining a luminous spot of fluorescence from the fluorescence measured.

6. A method for visualizing a structural defect of a surface of a substrate, according to claim 5, wherein said organic solvent is one selected from the group consisting of alcohols, ethers, and acetone.

7. A method for visualizing a structural defect of a surface of a substrate, according to claim 5, wherein said slip of paper is a slip of paper selected from the group consisting of lens cleaning paper, carbon base paper, and thin paper.

8. A method for visualizing a structural defect of a surface of a substrate, according to claim 5, wherein the concentration of said fluorescent molecules is 10^-4 M or less.

9. A method for visualizing a structural defect of a surface of a substrate, on the occasion of carrying out measurement of scattered light of the surface of the substrate wherein the fluorescent single molecules are distinguishable on the surface of the substrate;

on which fluorescent molecules are deposited, comprising the steps of;

dissolving said fluorescent molecules in a predetermined concentration in a volatile, organic solvent, thereby preparing a sample solution;

placing a slip of paper on a substrate where the measurement of scattered light is carried out;

dropping said sample solution onto said slip of paper placed on said substrate;

pulling said slip of paper so as to make the dropped sample solution traverse said surface of the substrate before said organic solvent evaporates, thereby placing the fluorescent single molecules on the surface of the substrate;

radiating laser light to the surface of said substrate on which said fluorescent single molecules are placed;

then measuring scattered light generated in said surface of the substrate; and

obtaining as luminous spot of scattered light from the scattered light measured.

10. A method for visualizing a structural defect of a surface of a substrate, according to claim 9, wherein said organic solvent is one selected from the group consisting of alcohols, ethers, and acetone.

11. A method for visualizing a structural defect of a surface of a substrate, according to claim 9, wherein said slip of paper is a slip of paper selected from the group consisting of lens cleaning paper, carbon base paper, and thin paper.

12. A method for visualizing a structural defect of a surface of a substrate, according to claim 9, wherein the concentration of said fluorescent molecules is 10^-4 M or less.