Abstract: A method for forming an optical package includes forming a patterned hard mask on a surface of a semiconductor wafer. The patterned hard mask includes a plurality of recesses defining positions of cavities to be formed in the semiconductor wafer. Additionally, the method includes forming a respective photoresist structure on the surface of the semiconductor wafer in the plurality of recesses. The method further includes performing a first etch process during which the semiconductor wafer is etched in the recesses at positions not covered by the photoresist structure. In addition, the method includes removing the photoresist structures after performing the first etch process and performing a second etch process after removing the photoresist structures. In the second etch process, the semiconductor wafer is etched in the recesses to form the cavities by lowering structures formed in the first etch process.

Abstract: According to an implementation, a method for manufacturing a microelectromechanical system mirror device is provided. A mirror portion of the mirror device is rotatable about a first axis having an associated first resonance frequency and a second axis different from the first axis and having an associated second resonance frequency. The method includes estimating a deviation of a first geometry parameter of the mirror device from a reference value, and adjusting a manufacturing step for the mirror device to modify a second geometry parameter of the mirror device different from the first geometry parameter such that a variation of a frequency ratio between the first resonance frequency and the second resonance frequency caused by the deviation of the first geometry parameter and the modifying of the second geometry parameter is below a predefined threshold.

Abstract: A semi-volatile particulate matter detection device is disclosed for detecting semi-volatile particulate matter in a gas flow. The device has a first filter stage for receiving the gas flow, the first filter stage being configured to capture particulate matter and to be heated to a temperature of at least 150° C. to volatilise semi-volatile particulate matter to produce semi-volatile vapour for passing through the first filter stage with the gas flow. The device also has a conveyance section downstream of the first filter stage to convey the gas flow and the semi-volatile vapour. A second filter stage is configured to receive the flow from the conveyance section. The temperature of the conveyance section and/or of the second filter stage is controllable so as to cause condensation of at least some of the semi-volatile vapour and collect it on the second filter stage. A detector is provided for detecting at least one characteristic of the condensed semi-volatile vapour on the second filter stage.

Abstract: A semi-volatile particulate matter detection device is disclosed for detecting semi-volatile particulate matter in a gas flow. The device has a first filter stage for receiving the gas flow, the first filter stage being configured to capture particulate matter and to be heated to a temperature of at least 150° C. to volatilise semi-volatile particulate matter to produce semi-volatile vapour for passing through the first filter stage with the gas flow. The device also has a conveyance section downstream of the first filter stage to convey the gas flow and the semi-volatile vapour. A second filter stage is configured to receive the flow from the conveyance section. The temperature of the conveyance section and/or of the second filter stage is controllable so as to cause condensation of at least some of the semi-volatile vapour and collect it on the second filter stage. A detector is provided for detecting at least one characteristic of the condensed semi-volatile vapour on the second filter stage.