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 1):
An optical system configured to reflect an input beam of light to form a reflected beam of light, the optical system comprising:\n a combination of\n an optically-isotropic block having rectangular facets including an input facet, and output facet opposite to the input facet, and multiple side facets connecting the input and output facets, and \n an optically-isotropic optical wedge element disposed along the output facet such as to not intersect an axis of symmetry of said input facet, \n and\n an optical surface disposed to redirect a portion of said input beam, that has entered said block through the input facet and traversed said block and the optical wedge element, towards said combination, \n wherein the input facet forms a right dihedral angle with each of the side facets and each of the side facets forms a right dihedral angle with each of neighboring side facets.

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): 0.737586995477927
- 35 USC 102 Novelty (BERT): 0.5225602091244587
- Combined Prediction Score: 0.7160843168425802
- Mean Citation Score: 309.48849
- Max Citation Score: 346.68204
- Similarity Product: 259.42911911029097

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

Dataset: test