PATENT CLAIM ANALYSIS

Application Number: 15866696
Application Type: Utility
Filing Date: 2018-01
Publication Date: 2018-05
Patent Classification: ["356", "508000"]

Abstract:
An encoder head configured for use with a lithographic exposure tool. The head is devoid of a multiplicity of stand-alone optical retroreflectors. The head includes a single, geometrically substantially perfect optically-isotropic cuboid complemented with optically-isotropic prismatic elements to form a contraption that, in combination with a diffraction grating disposed on a wafer-stage of the exposure tool, splits a single input beam of light delivered to the contraption into four measurement (sub-)beams of light (two in xz-plane, two in yz-plane) and causes each of these sub-beams traverse two prismatic elements and be retro-reflected internally within the cuboid to exit the encoder head at a non-zero angle with respect to the input beam of light, thereby solving problems of (i) structural complexity of a conventional encoder head for use in an exposure tool, (ii) burdensome alignment of the multitude of optical prisms in the process of forming such encoder head, and (iii) cyclic non-linear errors associated with measurements involving conventional corner-cubes-based encoder heads while, at the same time, reducing the geometrical footprint of the encoder head (without reducing the cross-section of the single input beam).

Claim (Index 31):
A method according to  claim 22 , further comprising\n with an optical detector unit, receiving light resulting from spatial overlap between the first output measurement beam and a corresponding first output reference beam, the first output reference beam having been formed from a second portion of light delivered to the encoder head of said exposure tool, and with a programmable computer processor, determining phase information characterizing interference between said first output measurement beam and said first output reference beam, the phase information representing said position of the target.

Metadata:
- Claim Count in Document: 11.0
- Percentile: 86.0
- Lexical Diversity: 1.96226
- Patent Class: 356.0
- Transitional Phrase Type: open
- Component Type: 1
- Foreign Priority: False
- Related Applications: ['15483887', '15800480', '13672234', '14880812', '14736118']

Analysis Scores:
- 35 USC 101 Eligibility (BERT): 0.737423227229306
- 35 USC 102 Novelty (BERT): 0.5213661840379453
- Combined Prediction Score: 0.71581752291017
- Mean Citation Score: 309.48849
- Max Citation Score: 346.68204
- Similarity Product: 280.58913889321803

Labels:
- Claim Label 101: 1
- Claim Label 102: 1
- Claim Label 103: 1
- Claim Label 112: 0
- Combined Label: 1
- Label 101 Adjusted: 1

Dataset: test