Planarizing method

• US 7,862,737 B2
• Filed: 08/10/2007
• Issued: 01/04/2011
• Est. Priority Date: 08/10/2007
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Yatsu, Hideyuki, Hatate, Hitoshi, Kamijima, Akifumi
• Primary Examiner(s): Norton; Nadine G
• Assistant Examiner(s): Duclair; Stephanie
• Application Number:
  US11/837,189
• Publication Number:
  US 20090039056A1
• Time in Patent Office: 1,243 Days
• Field of Search: None
• US Class Current: 216/88
• CPC Class Codes: G03F 7/00 Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor using photoresist structures for special production processes, see the relevant places, e.g. B44C, H01L, e.g. H01L21/00, H05K
• CPC Class Codes: G03F 7/2026 for the removal of unwanted material, e.g. image or background correction
• CPC Class Codes: G11B 5/3163 Fabrication methods or processes specially adapted for a particular head structure, e.g. using base layers for electroplating, using functional layers for masking, using energy or particle beams for shaping the structure or modifying the properties of the basic layers

Abstract

Provided is a planarizing method in which a planarization with high flatness can be performed, without being restricted by the distribution of film thickness in the applied resist film. The planarizing method comprises the steps of: forming a resist film on a film to be planarized formed on a substrate; exposing the resist film with the amounts of exposure light in respective sections into which an area in which the film to be planarized is formed is divided, the amounts of exposure light being determined so as to realize film thicknesses to be left for planarization of the resist film in the respective sections; developing the exposed resist film, to form a resist film pattern with a controlled distribution of film thickness; and etching the resist film pattern and the film to be planarized, until eliminating the thickness amounts to be eliminated of the film to be planarized.

Claims

1. A planarizing method comprising the steps of:

forming a resist film on a film to be planarized, the film to be planarized being formed on a substrate;

dividing an area in which the film to be planarized was formed into a plurality of sections of equal size, the plurality of sections including the film to be planarized;

determining for each section an intended film thickness after planarization of the film to be planarized;

determining a total etching time required to obtain the determined intended film thickness for each section after planarization, in a section including a portion of the film to be planarized with a smallest film thickness;

determining for each section a time to be taken for etching the resist film from the determined total etching time and a thickness amount to be eliminated from the film to be planarized;

determining for each section a film thickness to be left for planarization of the resist film from the determined time to be taken for etching the resist film for each section;

exposing for each section said resist film to an amount of exposure light, the amount of exposure light being determined so as to realize the determined film thickness to be left for planarization of said resist film;

developing the exposed resist film, to form a resist film pattern with a controlled film thickness in each section; and

etching said resist film pattern and said film to be planarized, until eliminating the thickness amounts to be eliminated of said film to be planarized.

2. The planarizing method as claimed in claim 1, wherein an area on which said resist film is formed is divided into sections each of which has a size equivalent to that of a window of a stepper, and then, the exposure in each of said sections is performed by using said stepper.

3. The planarizing method as claimed in claim 1, wherein the exposure in each of the sections is performed by using a gray-tone mask or a half-tone mask which realizes the required amounts of exposure light in the respective sections at one time.

4. The planarizing method as claimed in claim 1, wherein an ion milling method is used for the etching step.

5. The planarizing method as claimed in claim 1, wherein the sections are of equal size and aligned in a direction along a diameter of the substrate.

6. The planarizing method as claimed in claim 1, further comprising, after forming, measuring in each section the initial thickness of the film to be planarized and the initial thickness of the resist film.

7. The planarizing method as claimed in claim 1, wherein the required etching time for each section is determined from the initial film thicknesses of the film to be planarized and the intended film thickness after planarization.