Time projection chambers are useful for high energy particle physics, nuclear physics, and astronomy. To enhance the particle detection efficiency and performance of the projection chambers functional bilayer thin film coatings based on the atomic layer deposition method are utilized. Coating material selection is based on Auger neutralization process ion induced electron emission from metallic surfaces (e.g., Mo or W) combined with a high secondary electron emission coefficient. Application of high secondary electron emission materials (e.g., MgO and CaF2) enhances the multiplication of these emitted electrons from ion induction processes. Therefore, using suitable bilayer coatings the overall TPC signal detection efficiency can be increased.

Time projection chambers are useful for high energy particle physics, nuclear physics, and astronomy. To enhance the particle detection efficiency and performance of the projection chambers functional bilayer thin film coatings based on the atomic layer deposition method are utilized. Coating material selection is based on Auger neutralization process ion induced electron emission from metallic surfaces (e.g., Mo or W) combined with a high secondary electron emission coefficient. Application of high secondary electron emission materials (e.g., MgO and CaF2) enhances the multiplication of these emitted electrons from ion induction processes. Therefore, using suitable bilayer coatings the overall TPC signal detection efficiency can be increased.

The invention relates to two dimensional (2D) heterostructures and methods of fabricating the same. The 2D hetero structures are integration of borophene with graphene and 2D lateral and vertical hetero structures with sharp and rotationally commensurate interfaces. The rich bonding configurations of boron indicate that borophene can be integrated into a diverse range of 2D heterostructures.

The invention relates to two dimensional (2D) heterostructures and methods of fabricating the same. The 2D hetero structures are integration of borophene with graphene and 2D lateral and vertical hetero structures with sharp and rotationally commensurate interfaces. The rich bonding configurations of boron indicate that borophene can be integrated into a diverse range of 2D heterostructures.

A method of forming a structure is provided. The method includes supporting a substrate within a reaction chamber of a semiconductor processing system, flowing a silicon precursor and a germanium precursor into the reaction chamber, and forming a silicon-germanium layer overlaying the substrate with the silicon containing precursor and the germanium precursor. Concentration of the germanium precursor within the reaction chamber is increased during the forming of the silicon-germanium layer overlaying the substrate. Methods of forming film stack structures, semiconductor device structures, and semiconductor processing systems are also described.

A method of forming a structure is provided. The method includes supporting a substrate within a reaction chamber of a semiconductor processing system, flowing a silicon precursor and a germanium precursor into the reaction chamber, and forming a silicon-germanium layer overlaying the substrate with the silicon containing precursor and the germanium precursor. Concentration of the germanium precursor within the reaction chamber is increased during the forming of the silicon-germanium layer overlaying the substrate. Methods of forming film stack structures, semiconductor device structures, and semiconductor processing systems are also described.

Techniques for overcoating slanted structures and devices obtained using the techniques are disclosed. In some embodiments, a method of forming an overcoat layer on a surface-relief structure on a substrate includes receiving the substrate with the surface-relief structure. The surface-relief structure includes a plurality of ridges slanted with respect to the substrate, and a plurality of grooves each between two adjacent ridges. The method further includes depositing, in each cycle of a plurality of cycles, a uniform layer of an overcoat material on surfaces of the plurality of ridges and bottoms of the plurality of grooves. The deposited layers of the overcoat material and the plurality of ridges collectively form a light-coupling structure on the substrate. A surface of the overcoat layer is planar.

Techniques for overcoating slanted structures and devices obtained using the techniques are disclosed. In some embodiments, a method of forming an overcoat layer on a surface-relief structure on a substrate includes receiving the substrate with the surface-relief structure. The surface-relief structure includes a plurality of ridges slanted with respect to the substrate, and a plurality of grooves each between two adjacent ridges. The method further includes depositing, in each cycle of a plurality of cycles, a uniform layer of an overcoat material on surfaces of the plurality of ridges and bottoms of the plurality of grooves. The deposited layers of the overcoat material and the plurality of ridges collectively form a light-coupling structure on the substrate. A surface of the overcoat layer is planar.

A secondary electron emissive coating. The coating is formed by atomic layer deposition of CaF.sub.2 on a substrate by ALD half cycle exposure of an alkaline metal amidinate and ALD half cycle exposure of a fluorinated compound, where the deposition occurs at a reaction temperature greater than a highest sublimation temperature of the first metal precursor and the second metal precursor and less than 50° C. above the highest sublimation temperature.

A secondary electron emissive coating. The coating is formed by atomic layer deposition of CaF.sub.2 on a substrate by ALD half cycle exposure of an alkaline metal amidinate and ALD half cycle exposure of a fluorinated compound, where the deposition occurs at a reaction temperature greater than a highest sublimation temperature of the first metal precursor and the second metal precursor and less than 50° C. above the highest sublimation temperature.