A wet etching solution according to the present disclosure is an etching solution for selectively removing a second metal layer made of at least one of a cobalt-based material or a copper-based material from a semiconductor substrate while suppressing etching of a first metal layer made of a tungsten-based material, the first metal layer and the second metal layer being co-present on the semiconductor substrate, an oxide layer being formed on a surface layer of at least the at least one of a cobalt-based material or a copper-based material. The wet etching solution includes a solution in which a -diketone containing a trifluoromethyl group and a carbonyl group bonded together is dissolved in an organic solvent.

A wet etching solution according to the present disclosure is an etching solution for selectively removing a second metal layer made of at least one of a cobalt-based material or a copper-based material from a semiconductor substrate while suppressing etching of a first metal layer made of a tungsten-based material, the first metal layer and the second metal layer being co-present on the semiconductor substrate, an oxide layer being formed on a surface layer of at least the at least one of a cobalt-based material or a copper-based material. The wet etching solution includes a solution in which a -diketone containing a trifluoromethyl group and a carbonyl group bonded together is dissolved in an organic solvent.

A method for forming a porous silicon material can include forming a mixture of silicon, carbon, and an etchant element, solidifying the mixture, removing the etchant element to form pores within the silicon material. The porous silicon material can include a distribution of pores with an average pore diameter between about 10 nm and 500 nm, wherein the silicon particle comprises a silicon carbon composite comprising 1-5% carbon by mass, 1-5% oxygen by mass, and 90-98% silicon by mass.

A method for forming a porous silicon material can include forming a mixture of silicon, carbon, and an etchant element, solidifying the mixture, removing the etchant element to form pores within the silicon material. The porous silicon material can include a distribution of pores with an average pore diameter between about 10 nm and 500 nm, wherein the silicon particle comprises a silicon carbon composite comprising 1-5% carbon by mass, 1-5% oxygen by mass, and 90-98% silicon by mass.

A self-aligned tunable metamaterial is formed as a wire mesh. Self-aligned channel grids are formed in layers in a silicon substrate using deep trench formation and a high-temperature anneal. Vertical wells at the channels may also be etched. This may result in a three-dimensional mesh grid of metal and other material. In another embodiment, metallic beads are deposited at each intersection of the mesh grid, the grid is encased in a rigid medium, and the mesh grid is removed to form an artificial nanocrystal.

A method for recovering tin and/or tin alloy from a substrate comprising providing a substrate having tin and/or tin alloy thereon; contacting the tin and/or tin alloy with a stripping solution comprising an inorganic acid and a persulfate compound; recovering tin salt and/or tin alloy salt precipitated from the stripping solution; and recovering tin and/or tin alloy from the tin salt and/or tin alloy salt, respectively.

A method for recovering tin and/or tin alloy from a substrate comprising providing a substrate having tin and/or tin alloy thereon; contacting the tin and/or tin alloy with a stripping solution comprising an inorganic acid and a persulfate compound; recovering tin salt and/or tin alloy salt precipitated from the stripping solution; and recovering tin and/or tin alloy from the tin salt and/or tin alloy salt, respectively.

An etching solution composition of this disclosure contains hydrogen peroxide, an etching inhibitor, a chelating agent, an etching additive, fluorides, a stabilizer, and water. Etching uniformity is increased by adjusting a mass proportion of each component in the etching solution composition, so as to avoid loss of properties such as etching tapered angles, etching deviation, and etching straightness, thereby enhancing product quality.

The compositions of the present disclosure polish surfaces or substrates that at least partially include ruthenium. The composition includes a synergistic combination of ammonia and oxygenated halogen compound. The composition may further include abrasive and acid(s). A polishing composition for use on ruthenium materials may include ammonia, present in an amount of 0.01 wt % to 10 wt %, based on the total weight of the composition; hydrogen periodate, present in an amount of 0.01 wt % to 10 wt %, based on the total weight of the composition; silica, present in an amount of 0.01 wt % to 12 wt %, based on the total weight of the composition; and organic sulfonic add, present in an amount of 0.01 wt % to 10 wt %, based on the total weight of the composition, wherein the pH of the composition is between 6 and 8.

A microfluidic device useable for performing live cell computed tomography imaging is fabricated with a cover portion including a first wafer with at least one metal patterned thereon, a base portion including a second wafer with at least one metal patterned thereon and negative photoresist defining recesses therein, and a diffusive bonding layer including a negative photoresist arranged to join the cover portion and the base portion. A composition useful in live cell computer topography includes a long-chain polysaccharide at a concentration of from about 0.01% to about 10.0% in cell culture medium for supporting cell life while enabling cell rotation rate to be slowed to a speed commensurate with low light level imaging.