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US 8,138,483 B2Granted
Method of measuring phase of phase shift mask
AssigneeSamsung Electronics Co., Ltd.
InventorsDong-Gun Lee, Seong-Sue Kim
Life of this patent
Estimating the term…
Abstract
In a method of measuring a phase of a phase shift mask, initial extreme ultraviolet (EUV) light is divided into secondary EUV light portions. The secondary EUV light portions are irradiated onto the phase shift mask as incident EUV light portions, and the phase of the phase shift mask is measured from reflected incident EUV light portions.
Claims8
A method of measuring a phase of a phase shift mask, the method comprising:
- dividing initial extreme ultraviolet (EUV) light into secondary EUV light portions;
- irradiating the secondary EUV light portions onto the phase shift mask as incident EUV light portions;
- and
- measuring the phase of the phase shift mask from reflected incident EUV light portions reflected from the phase shift mask
- wherein irradiating the secondary EUV light portions onto the phase shift mask as incident EUV light portions comprises reflecting the secondary EUV light portions back towards the phase shift mask, and directing the reflected secondary EUV light portions towards the phase shift mask as the incident EUV light portions, and
- wherein reflecting the secondary EUV light portions back towards the phase shift mask comprises controlling a reflection angle for a first mirror, such that the reflected secondary EUV light portions are directed to a location above a path of the secondary EUV light portions.
3 more elements
A method of measuring a phase of a phase shift mask, the method comprising:
- dividing initial extreme ultraviolet (EUV) light into secondary EUV light portions;
- irradiating the secondary EUV light portions onto the phase shift mask as incident EUV light portions;
- and
- measuring the phase of the phase shift mask from reflected incident EUV light portions reflected from the phase shift mask
- wherein irradiating the secondary EUV light portions onto the phase shift mask as incident EUV light portions comprises reflecting the secondary EUV light portions back towards the phase shift mask, and directing the reflected secondary EUV light portions towards the phase shift mask as the incident EUV light portions, and
- wherein directing the reflected secondary EUV light portions towards the phase shift mask as the incident EUV light portions comprises controlling a reflection angle for a second mirror, such that the incident EUV light portions are directed to the phase shift mask at an incident angle ranging from between about 2° to 10° relative to a vertical axis perpendicular to a primary upper surface of the phase shift mask.
3 more elements
A method of measuring a phase of a phase shift mask, the method comprising:
- passing initial EUV light in a horizontal direction through a plurality of pinholes to divide the initial EUV light into secondary EUV light portions;
- reflecting the secondary EUV light portions back towards the phase shift mask;
- directing the reflected secondary EUV light portions towards the phase shift mask as incident EUV light portions;
- detecting reflected incident EUV light portions reflected from the phase shift mask;
- obtaining an interference fringe from the detected, reflected incident EUV light portions;
- and
- measuring a shift in the obtained interference fringe in relation to a reference interference fringe
- wherein directing the reflected secondary EUV light portions towards the phase shift mask as incident EUV light portions comprises:
- reflecting the secondary EUV light portions back towards the phase shift mask using a first mirror arranged in a horizontal path of the secondary EUV light portions;
- and
- directing the reflected secondary EUV light portions towards the phase shift mask as the incident EUV light portions using a second mirror arranged above the horizontal path of the secondary EUV light portions.
8 more elements
Dependencies are inferred from the claim text.