Microspectrometer with sacrificial layer integrated with integrated circuit on the same substrate

A process for fabricating a microspectrometer array over a semiconductor substrate, comprising the steps of:

• forming an integrated circuit with the semiconductor substrate;
• forming a first array of mirrors over the substrate;
• forming a sacrificial layer over the first array of mirrors;
• forming an array of bridge structures over the sacrificial layer and extending over the first array, the array of bridges having an array of second mirrors positioned over each of the first mirrors;
• removing the sacrificial layer to form a cavity between each first mirror and each second mirror to form a microspectrometer array on the common substrate;
• optically coupling a plurality of radiation detectors to the microspectrometer array, each radiation detector being optically coupled to a cavity such that radiation of a given spectral range that is transmitted through each cavity is incident upon the coupled detector, each detector generating an electrical signal correlated with the intensity of the radiation incident upon the detector;
• forming interconnects for the microspectrometer array on the common substrate to form a microspectrometer array circuit;
• and
• electrically connecting the plurality of radiation detectors with the interconnects to form an array detector circuit.

A process for fabricating a microspectrometer over a semiconductor substrate, comprising the steps of:

• forming an integrated circuit device from the semiconductor substrate;
• forming a first mirror over a semiconductor substrate;
• forming a sacrificial layer over the mirror;
• forming a bridge structure over the sacrificial layer and extending over the first mirror, the bridge having a second mirror positioned over the first mirror;
• removing the sacrificial layer to form a cavity between the first mirror and the second mirror, the second mirror being connected to a drive circuit in the integrated circuit;
• optically coupling a radiation detector to the cavity such that radiation of a given spectral range that is transmitted through the cavity is incident upon the detector, the detector generating an electrical signal correlated with the intensity of the radiation incident upon the detector;
• and
• optically coupling an optical fiber to deliver radiation to the cavity or receive radiation from the cavity.

A process for fabricating a microspectrometer over a substrate comprising the steps of:

• forming a first mirror over a substrate;
• forming a sacrificial layer over the mirror;
• depositing a bridge structure over the sacrificial layer and extending over the first mirror, the bridge having a second mirror positioned over the first mirror and formed with a diaphragm that is supported relative to the substrate by a plurality of springs;
• removing the sacrificial layer to form a cavity between the first mirror and the second mirror to provide a scanning microspectrometer device, the device including an actuator to control a distance between the first mirror and the second mirror, the actuator displacing the diaphragm relative to the substrate such that the diaphragm vibrates at a resonant frequency, the device further including a position sensor that measures the distance between the first mirror and the second mirror;
• optically coupling a radiation detector to the cavity such that radiation of a given spectral range that is transmitted through the cavity is incident upon the detector, the detector generating an electrical signal correlated with the intensity of the radiation incident upon the detector.