Method of manufacturing a device by means of a mask phase-shifiting mask for use in said method

• US 20010021477A1
• Filed: 01/29/2001
• Published: 09/13/2001
• Est. Priority Date: 03/03/2000
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Dirksen, Peter, Juffermans, Casparus Anthonius Henricus
• Granted Patent: US 6,544,694 B2
• Time in Patent Office: Days
• US Class Current: 430/5
• CPC Class Codes: G03F 1/26 Phase shift masks [PSM]; PSM blanks; Preparation thereof
• CPC Class Codes: G03F 1/32 Attenuating PSM [att-PSM], e.g. halftone PSM or PSM having semi-transparent phase shift portion,; Preparation thereof
• CPC Class Codes: G03F 1/36 Masks having proximity correction features; Preparation thereof, e.g. optical proximity correction [OPC] design processes

Abstract

A method is described for imaging, by means of projection radiation, a phaseshifting mask pattern on a substrate for the purpose of configuring device features in the substrate. By using a mask pattern comprising mask features constituted by a phase transition (22) and two sub-resolution assist features (40,41), arranged symmetrically with respect to the phase transition and having a mutual distance (p), device features having a wide variety of widths can be obtained by varying only the mutual distance.

Claims

1. A method of manufacturing a device in at least one layer on a substrate, comprising the steps of:

imaging, by means of projection radiation having a wavelength λ and

a projection system having a numerical aperture NA, a specific phase shifting mask pattern, comprising pattern features corresponding to device features to be configured in said layer, on a radiation-sensitive layer provided on said layer, and

removing material from, or adding material to, areas of said layer which are delineated by the mask pattern image, the smallest device features having a width which is smaller than λ

/NA, characterized in that use is made of a mask pattern comprising mask features which are constituted by the combination of a phase transition determining the position of the imaged mask feature in the device layer and the length of the imaged mask feature, and two sub-resolution assist features flanking the phase transition and having a specific mutual distance which substantially determines the width of the imaged mask feature in the device layer.

2. A method as claimed in

claim 1

, characterized in that the width of the imaged mask feature is tuned by adapting at least one of the following parameters:

the width of the assist features;

the transmission of the assist features, and

the phase shift introduced by the assist features.

3. A method as claimed in

claim 1

or

2

, characterized in that use is made of a mask pattern wherein the assist features are constituted by opaque strips.

4. A method as claimed in

claim 1

or

2

, characterized in that use is made of a mask pattern wherein the assist features are constituted by radiation attenuating strips.

5. A method as claimed in

claim 1

or

2

, characterized in that use is made of a mask pattern wherein the phase transitions are arranged in phase shifting areas which are embedded in opaque surroundings, and the assist features belonging to a specific phase transition are arranged within its phaseshifting area.

6. A lithographic phaseshifting mask for use with the method as claimed in

claim 1

for optically transferring a mask pattern, corresponding to a device layer structure, from said mask to a layer on a substrate, characterized in that said mask pattern comprises mask features which are constituted by the combination of a phase transition determining the position of the imaged mask feature in the device layer and the length of the imaged mask feature, and two sub-resolution assist features flanking the phase transition and having a specific mutual distance, which distance substantially determines the width of the imaged mask feature in the device layer.

7. A lithographic phaseshifting mask as claimed in

claim 6

, characterized in that the phase transitions are arranged in phaseshifting areas which are embedded in opaque surroundings, and the assist features belonging to a specific phase transition are arranged within its phaseshifting area.

8. A lithographic phaseshifting mask as claimed in

claim 6

or

7

, characterized in that the mask pattern is a transmission pattern.

9. A lithographic phaseshifting mask as claimed in

claim 6

or

7

, characterized in that the mask pattern is a reflective pattern.

10. A lithographic phaseshifting mask as claimed in

claim 6

,7, 8 or 9, characterized in that the assist features are constituted by opaque strips.

11. A lithographic phaseshifting mask as claimed in

claim 10

, characterized in that the material of the strips is chrome.

12. A lithographic phaseshifting mask as claimed in

claim 6

,7,8 or 9, characterized in that the assist features are constituted by radiation attenuating strips.

13. A lithographic phaseshifting mask as claimed in

claim 12

, characterized in that the material of the strips is a composition of molybdenum and silicon.