A method is provided for subtractively processing a layer of etchable material formed over an electrically conductive surface region of a workpiece. The workpiece is immersed in a liquid solution, generally but not exclusively a conductive solution, that comprises an etchant for the etchable material, so that etching of the etchable material is initiated. An electric circuit is connected to include a control electrode, a reference electrode, and the electrically conductive surface region of the workpiece. The electric circuit is used to monitor the development process dynamically at each of a plurality of intervals during the etching. The etching is terminated when the electrochemical signal satisfies a criterion indicating that the etching is complete.

Methods and apparatus for subtractively fabricating three-dimensional structures relative to a surface of a substrate and for additively depositing metal and dopant atoms onto the surface and for diffusing them into the bulk. A chemical solution is applied to the surface of the semiconductor substrate, and a spatial pattern of electron-hole pairs is generated by projecting a spatial pattern of illumination characterized by a specified intensity, wavelength and duration at each pixel of a plurality of pixels on the surface. Charge carriers are driven away from the surface of the semiconductor on a timescale short compared to the carrier recombination lifetime. Such methods are applied to creating a spatially varying doping profile in the semiconductor substrate, a photonic integrated circuit and an integrated photonic microfluidic circuit.

A method for fabricating a microelectromechanical system device. Submerging a microelectromechanical system device in water. The microelectromechanical system devices include a sacrificial layer deposited on the surface of a substrate between the portion of a structural layer to be freed for movement and a base. Anodically etching the sacrificial layer from the microelectromechanical device to free the portion of the structural layer for movement. A system comprising a solution of water, a microelectromechanical system device including a sacrificial layer of chromium deposited on the surface of a substrate between a portion of a structural layer and a base. The microelectromechanical system device is submerged in the solution of water. An electrode is submerged in the water. The electrode provides a negative bias. A voltage source provides a positive bias to the sacrificial layer of chromium, anodically etching the sacrificial layer of chromium and freeing the portion of the structural layer.

A method for fabricating a microelectromechanical system device. Submerging a microelectromechanical system device in water. The microelectromechanical system devices include a sacrificial layer deposited on the surface of a substrate between the portion of a structural layer to be freed for movement and a base. Anodically etching the sacrificial layer from the microelectromechanical device to free the portion of the structural layer for movement. A system comprising a solution of water, a microelectromechanical system device including a sacrificial layer of chromium deposited on the surface of a substrate between a portion of a structural layer and a base. The microelectromechanical system device is submerged in the solution of water. An electrode is submerged in the water. The electrode provides a negative bias. A voltage source provides a positive bias to the sacrificial layer of chromium, anodically etching the sacrificial layer of chromium and freeing the portion of the structural layer.

A semiconductor device production method includes performing trench etching to form a trench in a thickness direction of a semiconductor layer so that both of a first pattern portion and a second pattern portion whose side walls face each other across the trench are formed. In the trench etching, the semiconductor layer is etched and removed while a protective film is formed on a surface of the semiconductor layer, and the trench etching is performed so that the first pattern portion and the second pattern portion are configured to have a same potential or a same temperature during the trench etching.

A semiconductor device production method includes performing trench etching to form a trench in a thickness direction of a semiconductor layer so that both of a first pattern portion and a second pattern portion whose side walls face each other across the trench are formed. In the trench etching, the semiconductor layer is etched and removed while a protective film is formed on a surface of the semiconductor layer, and the trench etching is performed so that the first pattern portion and the second pattern portion are configured to have a same potential or a same temperature during the trench etching.

Methods and apparatus for subtractively fabricating three-dimensional structures relative to a surface of a substrate and for additively depositing metal and dopant atoms onto the surface and for diffusing them into the bulk. A chemical solution is applied to the surface of the semiconductor substrate, and a spatial pattern of electron-hole pairs is generated by projecting a spatial pattern of illumination characterized by a specified intensity, wavelength and duration at each pixel of a plurality of pixels on the surface. An electrical potential is applied across the interface of the semiconductor and the solution with a specified temporal profile relative to the temporal profile of the spatial pattern of illumination. Such methods are applied to the fabrication of a photodetector integral with a parabolic reflector, cell size sorting chips, a three-dimensional photonic bandgap chip, a photonic integrated circuit, and an integrated photonic microfluidic circuit.

Methods and apparatus for subtractively fabricating three-dimensional structures relative to a surface of a substrate and for additively depositing metal and dopant atoms onto the surface and for diffusing them into the bulk. A chemical solution is applied to the surface of the semiconductor substrate, and a spatial pattern of electron-hole pairs is generated by projecting a spatial pattern of illumination characterized by a specified intensity, wavelength and duration at each pixel of a plurality of pixels on the surface. Charge carriers are driven away from the surface of the semiconductor on a timescale short compared to the carrier recombination lifetime. Such methods are applied to creating a spatially varying doping profile in the semiconductor substrate, a photonic integrated circuit and an integrated photonic microfluidic circuit.

A method for producing at least one cavity within a semiconductor substrate includes dry etching the semiconductor substrate from a surface of the semiconductor substrate at at least one intended cavity location in order to obtain at least one provisional cavity. The method includes depositing a protective material with regard to a subsequent wet-etching process at the surface of the semiconductor substrate and at cavity surfaces of the at least one provisional cavity. Furthermore, the method includes removing the protective material at least at a section of a bottom of the at least one provisional cavity in order to expose the semiconductor substrate. This is followed by electrochemically etching the semiconductor substrate at the exposed section of the bottom of the at least one provisional cavity. A method for producing a micromechanical sensor system in which this type of cavity formation is used and a corresponding MEMS are also disclosed.