Research and development in integrated microelectronics have continued to produce astounding progress in CMOS and MEMS. CMOS technology has become the predominant fabrication technology for integrated circuits. MEMS technology continues to rely upon conventional processing. In layman's terms, microelectronic integrated circuits are the “brains” of an integrated device which provides decision-making capabilities, whereas MEMS are the “eyes” and “arms” that provide the ability to sense and control the environment. Some examples of the widespread application of these technologies are the switches in radio frequency (RF) antenna systems, and accelerometers in sensor-equipped game devices. These technologies are becoming ever more prevalent in society every day. Use of integrated circuits and MEMS has limitless applications through modular measurement devices such as accelerometers, gyroscopes, actuators, microphones, and sensors including magnetic field sensors, pressure sensors, humidity sensors, temperature sensors, chemical sensors, biosensors, and inertial sensors
Monolithic integration of MEMS devices and CMOS devices offers significant benefits enabling high volume production driving down the per-unit costs of sensor and actuator systems significantly. Micromechanical transducer systems not only need to receive analog and digital electrical inputs and transmit the output, but should also be able to measure rotation, strain, temperature, pressure, acceleration, infrared radiation, or micro fluidic chemical properties of liquids and gasses. Effective integration offers other benefits, including, simplifying interconnect issues, reduced packaging and fabrication complexity and significantly improving the overall performance and ease of use for the device.
One approach to the monolithic integration of CMOS and MEMS is to modify the complementary metal-oxide semiconductor (CMOS) foundry facility to fabricate micromechanical structures. In such an approach, CMOS devices and MEMS devices may be fabricated side-by-side on a semiconductor substrate. A disadvantage of this arrangement is cross talk caused by the MEMS devices and CMOS devices. Shielding has been proposed to reduce cross talk; however, use of shielding increases processing costs as well as the chip space required by the devices.
Accordingly, it is desirable to provide a method for fabricating an improved integrated MEMS-CMOS device. Further, it is desirable to provide an improved integrated MEMS-CMOS device. Also, it is desirable to provide an improved method for fabricating MEMS devices and CMOS devices on a substrate. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background.