The design of the collimator for dynamic infrared (IR) scene simulation based on the digital micro-mirror devices (DMD) is present in this paper. The collimator adopts a reimaging configuration to limit in physical size availability and cost. The aspheric lens is used in the relay optics to improve the image quality and simplify the optics configuration. The total internal reflection (TIR) prisms is located between the last surface of the optics and the DMD to fold the raypaths of the IR light source. The optics collimates the output from 1024×768 element DMD in the 8~10.3μm waveband and enables an imaging system to be tested out of 8° Field Of View (FOV). The long pupil distance of 800mm ensures the remote location seekers under the test.
Focal Plane Array (FPA) detector has characteristics of low cost, operating at room temperature, compatibility with the silicon CMOS technology, and high detecting performance, therefore it becomes a hot spot in infrared (IR) or terahertz (THz) detect field recently. However, the tradition structure of micro-bolometer has the conflict of the pixel size and thermal performance. In order to improve the detecting performance of small pixel size bolometer, high fill factor and low thermal conductance design should be considered. In IR detecting, double layers structure is an efficient method to improve the absorption of micro-bolometer and reduce thermal conductance. The three-dimension model of small size micro-bolometer was built in this article. The thermal and mechanical characters of those models were simulated and optimized, and finally the double layer structure micro-bolometer was fabricated with multifarious semiconductor recipes on the readout integrated chip wafer. For THz detecting, to improve the detecting performance, different dimension THz detectors based on micro-bridge structure were designed and fabricated to get optimizing micro-bolometer parameters from the test results of membrane deformation. A nanostructured titanium thin film absorber is integrated in the micro-bridge structure of the VOx micro-bolometer to enhance the absorption of THz radiation. Continuous-wave THz detection and imaging are demonstrated with a 2.52 THz far infrared CO2 laser and fabricated 320×240 vanadium oxide micro-bolometer focal plane array with optimized cell structure. With this detecting system, THz imaging of metal concealed in wiping cloth and envelope is demonstrated.
Patterning of AlCu alloy thin films is a key technology in MEMS fabrication. In this paper, reactive ion etching (RIE)
process of Al-1%Cu films was described using BCl3 and Cl2 as etching gases and N2 and CH4 as neutral gases. A four-step
process was presented to meet the etching requirements using BCl3, Cl2, N2 and CF4 as process gases. Optical emission
spectroscopy (OES) was used to monitor the state of the plasma in real time. The etching endpoint was detected by
detecting the spectral intensity change in the wavelength range of 395 ~ 400nm.
In order to increase the fill factor of small size micro-bolometer, double layer micro-bolometer was designed in this
paper with bottom sensitive/ top absorber structure. The deformation and residual stress characters of single layer and
double layer structure models were simulated and optimized, and with the optimized results, double layer structure
micro-bolometer was fabricated with multifarious semiconductor recipes. The surface image and deformation
information of the fabricated micro-bolometer was tested. By using double layer structure, the area of membrane
increases by a factor of 1.99 and 3.6 for the “L” shape leg structure and long “S” shape structure, respectively.