Integrated MEMS system

Abstract

To provide a 3D System ("3DS") MEMS architecture that enables the integration of MEMS devices with IC chips to form a System on Chip (SoC) or System in Package (SiP).SOLUTION: An integrated MEMS system 1000 comprises at least one MEMS chip 1100 including MEMS transducers 1170, and at least one IC chip including not only MEMS processing circuitry, but also additional / auxiliary circuitry to process auxiliary signals. The MEMS and IC chips are bump bonded. The MEMS chip includes first and second insulated conducting pathways. The first pathways conduct the MEMS-signals between the transducers and the IC chip, for processing; the second conducting pathways extend through the entire thickness of the MEMS chip to conduct auxiliary signals, such as power, RF, I / Os, to the IC chip, to be processed by the additional circuitry.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] Related Applications This patent application claims priority to U.S. patent application Ser. No. 61 / 925,379, the disclosure of which is incorporated by reference in its entirety into this patent application.

[0002] The present invention relates to the integration of microelectromechanical system (MEMS) devices such as sensors and actuators, and more particularly to integrated MEMS systems including integrated circuits (ICs) and MEMS chips. [Background technology]

[0003] Microelectromechanical systems (MEMS) devices, specifically inertial sensors such as accelerometers and angular rate sensors, or gyroscopes, are being used in an ever-increasing number of applications. The significant increase in consumer electronics applications for MEMS sensors, such as optical image stabilization (OIS) for cameras built into smartphones and tablet PCs, virtual reality systems, and wearable electronic devices, has sparked interest in utilizing such technology in more advanced applications traditionally served by much larger, more expensive, and higher-grade non-MEMS sensors. Such applications include single-axis and multi-axis devices for industrial applications, inertial measurement units (IMUs) for navigation systems and attitude heading reference systems (AHRSs), control systems for unmanned air, land, and sea vehicles, and indoor GPS-denied navigation for personal use. These applications may also include healthcare / medical and athletic performance monitoring systems, as well as advanced motion capture systems for next-generation virtual reality. These advanced applications often require lower bias drift and higher sensitivity specifications that far exceed the performance of existing consumer-grade MEMS inertial sensors on the market. To expand these markets and create new ones, it is desirable and necessary for more advanced performance specifications to be developed. There is also a need to produce low-cost, small-sized sensors and / or systems that can use MEMS inertial sensors.

[0004] Given that MEMS inertial sensors, such as accelerometers and gyroscopes, are typically much smaller than traditional mechanical gyroscopes, they are prone to greater mechanical noise and drift. Furthermore, because position and attitude are calculated by integrating acceleration and angular rate data, respectively, the noise and drift lead to increased errors. Therefore, for applications requiring high accuracy, such as navigation, it is generally desirable to augment the six-degree-of-freedom (6DOF) inertial capabilities of MEMS motion sensors (i.e., three axes of acceleration and three axes of angular rotation) with other position- and / or orientation-dependent measurements. Such sensor fusion is essential for achieving better results.

[0005] A pillar of the semiconductor industry's success has been the ever-increasing density of devices on silicon integrated circuits. Historically, this increase in density has been achieved by shrinking the minimum dimensions of electronic devices through improvements in photolithography and etching methods. Integrated circuit (IC) minimum dimensions have reached submicron dimensions, typically 180 nm, and state-of-the-art technologies of 10-20 nm. These dimensions are approaching the limits of conventional semiconductor processes, specifically the optical limits of photography. At the same time, Increasing the lateral chip dimensions in 2D to create larger chips has enhanced the overall chip functionality.

[0006] In reality, the electrical traces on the package substrate are much larger than those on the silicon chip. This mismatch leads to routing difficulties and excessive power consumption, and has led to the introduction of silicon (Si) interposers, where fine signal distribution traces are patterned on the chip side and coarse connections are patterned on the substrate side, with electrical interconnections between the two through the interposer. This approach using Si interposers is called 2.5D because the chips are distributed in 2D, but the interposer is introduced in the third dimension, including a few additional functions beyond passive elements such as resistors and capacitors.

[0007] The development of through-silicon vias (TSVs) enabled 3D integrated circuits (3DICs), in which individual IC chips are thinned and stacked. The introduction of TSV technology into IC processing introduced an additional level of complexity. While IC processing is typically constrained to a few microns near the surface of the IC chip and requires fine-feature photolithography, TSV processing involves coarser features and penetrates the thickness of the IC. Therefore, areas of the IC chip must be isolated for TSV fabrication, resulting in inefficient use of silicon area and higher IC unit cost. Furthermore, TSVs are typically filled with metal, specifically copper. Copper cannot be part of the front-end process due to the temperatures required to fabricate IC circuits. Therefore, TSVs must be made of polysilicon if they are fabricated early in the process, or late in the process if they are made of metal. Both approaches add complexity to semiconductor processes, which are typically highly controlled and difficult to alter.

[0008] In parallel with efforts to integrate more and more electrical functions into 3DICs, there is a desire to integrate MEMS into electronic devices. MEMS are integrated circuits containing mechanical, optical, magnetic, electrical, chemical, biological, or other tiny transducers or actuators. As electronic devices include more and more functions, designers must include MEMS sensors to provide feedback to users. For example, smartphones incorporate MEMS accelerometers and gyroscopes to provide motion information for the smartphone's location, gesture-based commands, navigation, and games. As electronic devices become smaller, more complex, and more integrated, there is a desire to include MEMS chips within system chips that contain integrated circuits for processing MEMS signals. However, there are some fundamental differences between many MEMS and IC fabrication processes. In most MEMS devices, MEMS mechanical elements (e.g., proof masses, micromirrors, micropumps, pressure-sensitive membranes) must be free to move. Therefore, additional fabrication steps must be added to free the MEMS mechanical elements. Additionally, because MEMS transducers are by design sensitive to some degree of environmental influence, the MEMS packaging must protect the transducer from undesirable environmental influences, which results in a more complex package than those used in standard IC packaging.

[0009] Efforts to integrate MEMS transducers with their sensing electronics ICs have been underway for several years. These efforts include side-by-side packaging of the MEMS and IC, assembling the MEMS directly onto the IC, and stacking the MEMS and IC. A drawback of these approaches is that they generally require additional final packaging, including a cap to protect the MEMS and wire bonds to make the electrical connection to the IC. This chip-scale packaging adds significant cost to the final device. The cap on the MEMS also makes stacking of chips for 3DIC applications difficult, if not impossible.

[0010] U.S. Patent No. 8,250,921 describes an integrated motion processing unit. Several individual MEMS sensors, each with an associated independent mixed-signal chip (ADC) for analog drive and sensing, filtering, and A / D conversion, are mounted on a substrate within a board or system box. Additional chips are included on the system board for calibration, system control, power management, and I / O. The costs of packaging the individual chips, fabricating the board, mounting the chips, and mechanical alignment make this approach expensive and primarily useful for high-margin applications such as navigation. Furthermore, the cover wafer contains no connectivity or electronic functions, merely a protective function.

[0011] Adding more and more MEMS functions to fewer MEMS chips and incorporating more electronic functions into fewer ICs can reduce cost and size, and it is desirable to integrate all of the MEMS sensors and electronics onto a single substrate. Typically, existing "single-chip" inertial measurement units (IMUs) consist of a bare chip that is wire-bonded to a package substrate that is affixed to each other and covered with a cap or plastic molding. Therefore, further 3D integration is not possible outside of the system components within the chip. Summary of the Invention [Problem to be solved by the invention]

[0012] The present invention provides a three-dimensional (3D) MEMS architecture that enables the integration of MEMS devices with IC chips to form MEMS-enabled system chips ("3DS"). [Means for solving the problem]

[0013] According to one aspect of the present invention, there is provided an integrated MEMS system, in one possible embodiment, the integrated MEMS system includes at least one single MEMS chip and at least one IC chip.

[0014] The MEMS chip includes a first cap layer including first and second sets of first cap MEMS electrical contacts. The MEMS also includes a second cap layer including second cap MEMS electrical contacts. The first and second cap MEMS electrical contacts are preferably bond pads. A central MEMS layer is disposed between the first cap layer and the second cap layer. At least one transducer is formed in the first cap layer, the central MEMS layer, and the second cap layer to generate motion or sense at least one parameter. First insulating conductive paths connect one or more transducers to the first set of first MEMS electrical contacts, respectively, to conduct electrical MEMS signals between the transducers and the first set of first cap MEMS electrical contacts. A second insulating conductive path connects the second set of first cap MEMS electrical contacts to at least some of the second cap MEMS electrical contacts through the first cap layer, the central MEMS layer, and the second cap layer to conduct auxiliary signals through the MEMS chip.

[0015] The single IC chip includes first and second sets of IC electrical contacts that are bump-bonded to the first and second sets of first cap MEMS electrical contacts, respectively. The single IC chip includes a MEMS signal processing device operatively connected to the first set of IC electrical contacts for processing electrical MEMS signals. and auxiliary signal processing circuitry operably connected to the second set of IC electrical contacts for processing auxiliary signals and providing additional system functionality.

[0016] The first cap layer, the central MEMS layer, and the second cap layer are preferably made of an electrically conductive material, with the first cap layer electrically bonded to a first side of the central MEMS layer and the second cap layer electrically bonded to a second side of the central MEMS layer opposite the first side. More specifically, the first cap layer, the central MEMS layer, and the second cap layer are preferably fabricated from respective silicon-based wafers that are bonded at wafer level.

[0017] In some embodiments, the central MEMS layer is made from a silicon-on-insulator wafer.

[0018] In some embodiments, the second insulating conductive path is formed by trenches etched into one of the first layer, the central MEMS layer, and the second layer. The trenches are aligned and filled with an insulating material. The trenches surround respective conductive wafer plugs, which enable transmission of electrical signals through the entire thickness of the MEMS chip.

[0019] In some embodiments, at least some of the second insulating conductive paths are formed by trenches etched into one of the first layer, the central MEMS layer, and the second layer, the trenches being aligned and having their respective sidewalls lined with an insulating material and filled with a conductive material.

[0020] In some embodiments, the transducer comprises a six degree of freedom motion sensor, and the parameters include three axes of linear acceleration and three axes of angular velocity.

[0021] In some embodiments, the six degrees of freedom motion sensor includes first and second sets of electrodes disposed in the first and second cap layers, respectively, and a plurality of proof masses disposed in the central MEMS layer, the first and second sets of electrodes forming capacitors with the proof masses, and some of the first insulating conductive paths connecting the electrodes of the first and second sets of electrodes to at least some of the first cap MEMS electrical contacts of the first set of MEMS electrical contacts, respectively.

[0022] In some embodiments, the at least one transducer includes at least one non-inertial sensor, such as a pressure sensor, a magnetometer, a thermometer, and a microphone. The non-inertial sensor typically includes a non-inertial electrode patterned in the first or second layer and at least one MEMS structure patterned in the central MEMS layer. Some of the first insulating conductive paths connect the non-inertial electrode to at least some of the first set of first cap MEMS electrical contacts.

[0023] The electrical MEMS signals are most often analog signals, and the IC chip includes mixed-signal CMOS circuitry to convert the analog signals transmitted by the MEMS chip into digital signals for processing by the MEMS signal processing circuitry, and to convert the digital signals transmitted by the MEMS signal processing circuitry back into analog signals before entering the MEMS chip.

[0024] In some embodiments, the IC chip includes a digital bus, and the MEMS signal processing circuit includes a digital CMOS circuit connected to the mixed signal circuit via the digital bus. The digital CMOS circuit may include a digital data analysis circuit, a digital input / output circuit, a memory, The system may include at least one of a system controller and a calibration / compensation circuit.

[0025] In some embodiments, the IC chip includes a power bus, and the auxiliary signal processing circuitry includes a power management circuit connected to the power bus and the digital bus. The IC chip may also include high-speed CMOS circuitry connected to the digital bus for processing the auxiliary signal. The high-speed CMOS circuitry may include an input / output module for wireless signals or GPS signals.

[0026] In some embodiments, the integrated MEMS system includes a first single MEMS chip and at least one additional single MEMS chip. The first single MEMS chip and the at least one additional single MEMS chip are stacked vertically, i.e., one above the other, with a second layer of the first single MEMS chip bump-bonded to a first layer of the at least one additional single MEMS chip. Second insulating conductive paths of the at least one additional single MEMS chip are electrically connected to at least some of the second insulating conductive paths of the first single MEMS chip to conduct auxiliary signals through the first single MEMS chip and the at least one additional single MEMS chip to the at least one IC chip.

[0027] The first MEMS chip preferably includes a third set of first cap MEMS electrical contacts and third insulating conductive paths connecting the third set of first cap MEMS electrical contacts to at least some of the second cap MEMS electrical contacts through the first cap layer, the central MEMS layer, and the second cap layer. The third insulating conductive paths are electrically connected to the MEMS signal processing circuitry of the IC chip and to the insulating conductive paths of the at least one additional single MEMS chip. Thus, the MEMS signal processing circuitry can process electrical MEMS signals of the first single MEMS chip and the additional single MEMS chip.

[0028] In some embodiments, the integrated MEMS system may include a first single IC chip and at least one additional single IC chip.

[0029] Of course, other processing steps may occur before, during, or after each of the above steps, the order of the steps may also vary, and some of the steps may even be combined.

[0030] It should be noted that the drawings depict only exemplary embodiments of the invention and therefore should not be construed as limiting the scope of the invention, which may admit of other equally effective embodiments. [Brief explanation of the drawings]

[0031] [Figure 1A] 1 is a schematic, partially exploded perspective view of an integrated MEMS system according to one embodiment; [Figure 1B] 1B is a schematic exploded perspective view of the integrated MEMS system of FIG. 1A. [Figure 2A] 1 is a schematic cross-sectional view of an integrated MEMS system according to another embodiment. [Figure 2B] 10A-10C are detailed views of insulating conductive paths formed in a MEMS chip, showing possible variations. [Figure 2C] 10A-10C are detailed views of insulating conductive paths formed in a MEMS chip, showing possible variations. [Figure 2D] 1 is a schematic cross-sectional view of an integrated circuit wafer. [Figure 2E] FIG. 1 is a schematic cross-sectional view of a MEMS wafer stack. [Figure 2F] 2D to the MEMS wafer stack of FIG. 2E. [Figure 2G] 2B is a schematic cross-sectional view of the integrated MEMS system of FIG. 2A bonded to a printed circuit board (PCB). [Figure 3] 1 is a schematic diagram of an integrated MEMS system according to one possible embodiment. [Figure 4A] FIG. 1 is a schematic cross-sectional view of an IC wafer and two MEMS wafer stacks bonded at wafer level. [Figure 4B]1 is a schematic cross-sectional view of an integrated MEMS system according to one possible embodiment shown bonded to a PCB. [Figure 5A] FIG. 5A is a schematic cross-sectional view of a MEMS wafer stack and several IC chips bump-bonded to the MEMS wafer stack. [Figure 5B] FIG. 5B is a schematic cross-sectional view of an integrated MEMS system according to another possible embodiment shown bonded to a PCB. DETAILED DESCRIPTION OF THE INVENTION

[0032] In the following description, like features in the figures are given like reference numerals, and in order to maintain clarity of the figures, the same reference numerals may be omitted if they have already been shown in a previous figure. It should also be understood that the elements in the figures are not necessarily drawn to scale, with emphasis being placed on clearly illustrating the elements and structure of the present embodiment.

[0033] Throughout this description, terms such as “top” and “bottom,” “above” and “below,” “on” and “below,” “upper” and “lower,” and other equivalent terms indicating the location of one element relative to another, as shown in the figures, are used herein for ease of description and clarity and should not be considered limiting. It will be understood that such spatial relationship terms are intended to encompass various orientations of the MEMS chip during use or operation in addition to the orientation illustrated in the figures. In particular, the terms “top” and “bottom” are used to facilitate interpretation of the description, and those skilled in the art of MEMS will readily recognize that, in use, the MEMS sensor can be positioned in different orientations such that the “top cap” and “bottom cap” are positioned upside down.

[0034] Additionally, the term MEMS transducer encompasses devices such as, but not limited to, accelerometers, gyroscopes, pressure sensors, magnetometers, actuators, microfluidic devices, micro-optical devices, etc. IC chips may also include microelectronic circuits such as power amplifiers, detection circuits, GPS, microprocessors, etc. The term "MEMS portion" of the integrated MEMS system described herein may also be referred to as a multi-wafer stack 3DS MEMS.

[0035] MEMS systems are generally mixed-signal (analog and digital) systems. While MEMS chips are typically analog and contain continuously variable transducers (sensors or actuators), the data acquired or provided to drive the MEMS is most often used or generated digitally. MEMS chips can have one or more analog input / output (I / O) channels, and electronic systems can have both analog and digital outputs. Analog MEMS channels can be used to transmit MEMS sensor output to a digital system and to provide analog signals to the MEMS for actuation or sensor operation. Typically, MEMS can interface with an analog-to-digital converter (ADC), which can amplify and convert the MEMS sensor output to digital form and / or convert the digital signal to an analog voltage or current that can be used to actuate the MEMS. Beyond this interface, most data processing can be digital.

[0036] Broadly speaking, the present invention is directed to an integrated MEMS system. The integrated MEMS system is fabricated from a multi-wafer MEMS stack including first and second cap wafers and a central MEMS wafer, which can be a standard wafer, a silicon-on-insulator (SOI) wafer, or multiple wafers. The multi-wafer stack is configured with isolated conductive paths, also known as 3D through-chip vias (3DTCV). These isolated conductive paths are formed by patterning trenches in the silicon wafer around plugs of silicon. The trenches are filled or covered with an insulating material to insulate the silicon plugs. The silicon plugs of the first wafer, the central MEMS wafer, and the second wafer are aligned to form isolated conductive paths, some of which extend through the entire thickness of the multi-wafer stack. The insulating conductive paths allow signals to travel from the bond pads on the first cap layer and from electrodes on the first wafer, second wafer, and / or central MEMS wafer through the central MEMS wafer and second cap wafer to the bond pads on the second cap wafer. An IC wafer is bump-bonded to the first or second cap layer of the multi-wafer stack and diced to form a singulated or individual integrated MEMS system. This configuration provides electrical routing between the multi-wafer MEMS stack and the integrated circuit, as the integrated circuit I / O pads are bump-bonded to pads on one of the first and second caps. After dicing, the individual components are integrated MEMS systems that can be bump-bonded to a PCB, eliminating the need for bond wires and external packaging.

[0037] 1A and 1B, one possible embodiment of an integrated MEMS system 1000 is shown. The system 1000 has an architecture that can enable the integration of MEMS sensor functionality on a single MEMS chip while simultaneously integrating electronic functionality on a single IC chip. This architecture allows auxiliary signals to be passed through the MEMS chip for processing by the IC chip. The MEMS chip includes multiple insulated conductive paths, some of which extend somewhat through the entire thickness of the MEMS chip, allowing for wire-bond-free electrical connections to the IC chip. The auxiliary signals are non-MEMS signals, i.e., external to the MEMS chip and provided by another component, such as a PCB. The IC chip can be flip-chip bonded on top of the MEMS chip at the chip or wafer level to form an integrated MEMS system, eliminating much of the cost of MEMS and IC integration, as well as the packaging complications and costs mentioned above. The MEMS system can also include several single MEMS chips stacked vertically, and possibly two or more IC chips.

[0038] In this example, the integrated MEMS system 1000 comprises a single MEMS chip 1100 including a first cap layer 1120, a central MEMS layer 1160, and a second cap layer 1140. Each of the layers 1120, 1160, and 1140 is made of a conductive material, such as silicon. The first cap layer 1120 is electrically bonded to a first side 1161 of the central MEMS layer 1160, and the second cap layer 1140 is electrically bonded to a second side 1162 of the central MEMS layer 1160 opposite the first side 1161. The central MEMS layer 1160 is disposed between the first cap layer 1120 and the second cap layer 1140 and is made of a silicon-on-insulator (SOI) wafer including a device layer 1164, a handle layer 1168, and an insulating layer 1166. The first cap layer 1120, the central MEMS layer 1160, and the second cap layer 1140 are fabricated from respective silicon-based wafers that are wafer-level bonded, as described in more detail below. The insulating layer 1166 is a SOI buried oxide layer between the SOI device layer 1164 and the SOI handle layer 1168. A conductive shunt may be formed in the buried oxide to make an electrical connection at a specific desired location between the SOI device layer 1164 and the SOI handle layer 1168, for example as part of an insulating conduction path. The insulating layer 1166 is fabricated through the insulating layer 1166 .

[0039] At least one transducer 1170 is formed in the first cap layer 1120, the central MEMS layer 1160, and the second cap layer 1140 to induce motion or sense at least one parameter. The transducer can be a sensor, such as a motion sensor, or an actuator, such as a microswitch. One or more transducers include a MEMS structure, such as a proof mass for a motion sensor or a membrane for a pressure sensor or magnetometer. The architecture of the MEMS chip 1100, with two interconnected outer caps and the central MEMS layer made of conductive material, allows for the inclusion of several different types of transducers within a single MEMS chip. The MEMS structure is patterned in the central MEMS layer 1160, and first and second electrode sets 1180, 1182 are patterned in the first and second layers 1120, 1140 and operatively associated (magnetically, capacitively, electrically, etc.) with the MEMS structure. Thus, a "single MEMS chip" is a chip that includes one or more MEMS transducers patterned within the two cap layers 1120 and 1140 and the central MEMS layer 1160. The various MEMS features or functions of the transducers (i.e., electrodes, proof masses, membranes, leads, etc.) are patterned within the same silicon wafer, as opposed to bonding multiple MEMS chips side-by-side on a substrate, with each chip containing a different MEMS sensor. For example, the present architecture allows MEMS features or functions for measuring acceleration, angular velocity, and magnetic fields along three different axes, as well as other sensors such as pressure sensors, to be patterned within the same three wafer layers, and therefore within the same MEMS chip.

[0040] 1A and 1B, the first cap layer 1120 includes electrical contacts 1124, 1126 on its exterior, preferably disposed around the periphery of the MEMS chip 1100. These first cap layer electrical contacts 1124, 1126 are referred to as first cap MEMS electrical contacts. The second cap layer 1140 also includes electrical contacts 1144 on its exterior, referred to as second cap MEMS electrical contacts. The first and second cap MEMS electrical contacts 1124, 1126, and 1144 are typically bond pads.

[0041] The single MEMS chip 1100 also includes a plurality of insulated conductive paths 1130, 1150 that extend through one or more of the first cap layer 1120, the central MEMS layer 1160, and the second layer 1140. Thus, the MEMS chip includes electrically isolated “three dimensional through-chip vias (3DTCVs)” for transmitting signals through the MEMS wafer layer 1160 to the cap layers 1120, 1140 and through the cap layers 1120, 1140 to bond pads 1124, 1144 on the outside of the MEMS chip. The insulated conductive paths 1130, 1150 can extend in one or more directions. The insulated conductive paths 1130, 1150 can be formed using a silicon “trench-and-fill” method. The insulating conductive paths 1130, 1150 are typically formed by an insulated closed-loop trench 28 surrounding a conductive wafer plug 26. The trench 28 is filled with an insulating material, and the conductive wafer plug 26 enables the transmission of electrical signals. The insulating conductive paths 1130, 1150 have portions that extend into one or more layers and are aligned at the layer interface to enable the conduction of electrical signals through the MEMS chip 1100. Some of the insulating conductive paths connect one or more transducers to first cap MEMS electrical contacts that are part of the first set of contacts 1124. These insulating conductive paths are referred to as first insulating conductive paths 1130. They conduct electrical MEMS signals between the transducer 1170 and the first cap MEMS electrical contacts of said first set 1124. More specifically, the insulating conductive paths 1130 connect the electrodes, leads, and / or MEMS of the transducer 1170. The first cap layer 1120 and the second cap layer 1140 are electrically isolated from each other by insulating conductive paths 1150. These paths connect the first cap MEMS structure to the first cap MEMS electrical contacts 1124. Other insulating conductive paths extend through the entire thickness of the single MEMS chip 1100, i.e., through the first cap layer 1120, the central MEMS layer 1160, and the second cap layer 1140. These insulating conductive paths connect the second set of first cap MEMS electrical contacts 1126 to some of the second cap MEMS electrical contacts 1144. They are called second insulating conductive paths 1150 and serve to conduct auxiliary signals, such as power signals or digital signals, through the MEMS chip 1100. The second insulating conductive paths 1150 provide an isolated path between the metallization and bond pads on the first cap layer 1120 and the bond pads on the second cap layer 1140 to send signals from the IC chip 1200 through the MEMS chip 1100 to another IC chip or to a PC board.

[0042] 1A and 1B, the integrated MEMS system 1000 also includes a single IC chip 1200. The IC chip 1200 is typically an application-specific integrated circuit (ASIC) chip fabricated using complementary metal-oxide-semiconductor (CMOS) technology, although other types of ICs can be used. The IC chip 1200 includes a MEMS signal processing circuit 1240 operably connected to the first isolated conductive path 1130 for processing electrical MEMS signals of one or more transducers 1170. The IC chip 1200 also includes an auxiliary signal processing circuit 1260 operably connected to the second isolated conductive path 1150 for processing auxiliary signals and for providing additional system functionality. Management functions performed by the IC may include interpretation of sensor data, compensation for variations in sensor response due to temperature or other environmental variations, microcontroller management of system timing and function, memory for storing data such as calibration constants, sensor interpretation constants, and measured data, and wired and wireless data I / O.

[0043] MEMS signal processing circuitry 1240 manages data signals to and from MEMS transducer 1170. MEMS signal processing circuitry 1240 controls and provides analog drive and feedback signals required by the transducer, controls the timing of signal measurements, amplifies, filters, and digitizes measured signals, and analyzes and interprets incoming MEMS signals from transducer 1170 to calculate various parameters such as angular acceleration or ambient pressure. MEMS signal processing circuitry 1240 typically includes at least A / D and D / A converters, a power supply, a system controller, memory, a calibration and synthesis module, and a data analysis module.

[0044] The auxiliary signal processing circuit 1260 processes signals other than those strictly required to operate the MEMS transducers and output measured MEMS signals. The auxiliary signal processing circuit 1260 may also provide additional system functions, such as monitoring sensor activity to minimize power usage, wirelessly transmitting and receiving data, receiving and interpreting GPS signals, integrating additional data from other sensors or the GPS for calibration or performance enhancement, and using measured data to calculate additional system parameters of interest or to trigger other system activities. When fully utilized, the auxiliary signal processing circuit 1260 can receive, process, and transmit signals other than MEMS signals, for example, from / to the PCB board, enabling the integrated 3D system 1000 to control, perform, and analyze measurements by the integrated MEMS sensors, act as a sensor hub between the 3DS system chip, other attached external sensors, and larger external systems such as a cell phone, game controller, or display device, and integrate all data to make decisions or provide input to the larger system. The MEMS chip also acts as a “smart” interposer between the PCB and the IC chip. Digital and / or analog signals passes through the MEMS chip, is processed by auxiliary circuitry 1260, can be used by the MEMS transducer 1170 (e.g., for power signals), and can be sent back through the MEMS chip or transmitted wirelessly.

[0045] Thus, the IC chip 1200 includes IC electrical contacts that are bump-bonded to the MEMS electrical contacts of the first cap layer 1120. The IC electrical contacts are grouped into first and second sets 1128, 1230 that are bump-bonded to first and second sets 1124, 1126 of first cap MEMS electrical contacts, respectively. In other words, the set 1128 of IC electrical contacts is connected to the set 1124 of MEMS electrical contacts, thus connecting the first isolated conductive path 1130 to the MEMS signal processing circuitry 1240. The set 1230 of IC electrical contacts is connected to the set 1126 of MEMS electrical contacts, thus connecting the second isolated conductive path 1150 to the auxiliary signal processing circuitry 1260. Typically, the MEMS electrical contacts of the first and second cap layers are bond pads.

[0046] 2A, there is shown another possible embodiment of an integrated MEMS system 2000. The exemplary 3DS MEMS chip 2100 is an enclosed 9 degree-of-freedom (DOF) MEMS sensor chip that includes a 6DOF inertial sensor 2172 for measuring x, y, and z acceleration and angular rate, and a 3-axis magnetometer 2176, all monolithically fabricated within the MEMS chip 2100.

[0047] The 6DOF inertial sensor 2172 senses three-axis linear acceleration and three-axis angular velocity. The 6DOF inertial sensor 2172 includes first and second electrode pairs 2180, 2182 disposed in the first and second cap layers 2120, 2140, respectively. One or several proof masses 2163, 2165 are patterned in the central MEMS layer 2160, and the first and second electrode pairs 2180, 2182 may form capacitors with the proof masses. While only two proof masses 2163, 2165 are shown in FIG. 2A , the 6DOF inertial sensor 2172 can include more proof masses. The MEMS chip 2100 includes first and second insulating conductive paths 2130, 2150 similar to those previously described. A first insulating conductive path 2130 connects the MEMS electrodes 2180, 2182 to a first set 2124 of MEMS electrical contacts on the first cap layer 2120. A second insulating conductive path 2150 extends through the entire thickness of the MEMS chip 2100 to allow transmission of auxiliary (or additional) signals through the MEMS chip 2100. The second insulating conductive path 2150 connects the second set 2126 of MEMS electrical contacts of the first cap layer 2120 to some of the MEMS electrical contacts 2144 of the second cap layer 2140. For clarity, only some of the first insulating conductive paths are shown in Figure 2A, such as paths 2130a, 2130d extending between the second cap electrode 2182 and the MEMS electrical contact 2124 of the first cap layer 2120, and paths 2130b and 2130c connecting the first cap electrode 2180 patterned in the first layer 2120 with the MEMS electrical contact 2126 of the same layer 2120. Similarly, only some of the second insulating conductive paths are shown in Figure 2A, such as paths 2150a and 2150b connecting the electrical contacts 2124, 2126 in the first cap layer 2120 with the electrical contact 2144 in the second cap layer 2140.

[0048] 2B and 2C, enlarged portions of possible variations of the insulating conductive path are shown. In FIG. 2B, the insulating path is formed by a closed-loop trench 28 surrounding a conductive wafer plug 26. The trench has its respective sidewalls lined with insulating material 30 and is filled with conductive material 32.

[0049] Alternatively, the trench may be completely filled with insulating material 30, as in FIG. 2C. For both variations, the conductive wafer plugs 26 allow electrical signals to be transmitted through the cap layer to the electrical contacts 42. Of course, since the insulating conductive paths can extend through the entire thickness of the MEMS chip, the central and second layers can be patterned identically so that the trenches in the first, central, and second layers are aligned at the contact surfaces of the layers.

[0050] Referring back to FIG. 2A , the single MEMS chip can also include a transducer that is a non-inertial sensor. Examples of usable non-inertial sensors include pressure sensors, magnetometers, thermometers, microphones, microfluidic devices, and micro-optical devices. Other types of non-inertial sensors can also be used. The non-inertial sensor includes a non-inertial electrode patterned on at least one of the first and second layers. The non-inertial sensor also includes at least one MEMS structure patterned in the central MEMS layer that can include the non-inertial electrode. Examples of MEMS structures in non-inertial sensors include membranes such as those used in pressure sensors, microphones, or magnetometers. Some of the first insulating conductive paths in the MEMS chip connect the non-inertial electrodes to at least some of the first cap MEMS electrical contacts to transmit signals from the non-inertial electrodes to bond pads on the first layer of the MEMS chip, and at least some of these first cap MEMS electrical contacts are connected to the IC chip.

[0051] 2A , the non-inertial sensor is a three-axis magnetometer 2176 that can be used to increase the accuracy of the inertial sensor 2172. The IC electrical contacts 2228, 2230 (such as IC I / O bond pads) of the single IC chip 2200 are bonded directly to the MEMS electrical contacts 2126, 2124 (such as MEMS I / O bond pads) of the single MEMS chip 2100 to reduce electrical noise and eliminate wire bonds. The magnetometer 2176 includes non-inertial electrodes, such as electrode 2184, and resonant membranes 2167, 2169.

[0052] Analog data can be communicated between the MEMS sensors 2172, 2176 and the IC chip 2200 at the IC chip's analog-to-digital converter (ADC) input / output mixed-signal stage. The MEMS signals generated by the sensors 2172, 2176 are analog signals, and therefore are converted to digital form by the ADC for further processing in the digital CMOS portion of the IC chip 2200. Data processing of the MEMS signals by the IC chip 2200 can include, for example, sensor calibration and compensation, navigational calculations, data averaging, or sensor data fusion. System control can be provided by an integrated microcontroller that can control data multiplexing, timing, calculations, and other data processing. Auxiliary (or additional) signals are communicated to the IC chip via additional digital I / O. The IC chip 2200 includes auxiliary signal processing circuitry, such as wireless communication or GPS (Global Positioning System) functionality. GPS data may also be used to augment and combine MEMS sensor data to increase the accuracy of MEMS sensor chip 2100. These are merely examples, and there may be more or less functionality in any particular system implementation. As can be appreciated, in addition to providing analog sensed data via MEMS signals, MEMS chip 2100 may also provide an electronic interface, including power, analog, and digital I / O, between MEMS system 2000 and the outside world, such as a printed circuit board in a larger system.

[0053] As in the embodiment shown in Figure 2A, a single MEMS chip 2100 is integrated into a 3D MEMS system 2000 (3DS) and functions as both an active MEMS device and an interposer for signal distribution. One possible use of the 3DS architecture involves wafer-scale integration of MEMS and ICs, as shown schematically in Figures 2D through 2H.

[0054] FIG. 2D is a schematic diagram of an IC wafer 200. The IC wafer may be constructed using any one of CMOS, gallium arsenide (GaAs) or other III-V compounds, indium phosphide (InP) or other II-VI compounds, silicon carbide, or other technologies. The IC wafer 200 includes several IC chips 2200. Each IC chip includes MEMS signal processing circuitry 2240 and auxiliary processing circuitry 2260 formed by IC transistors. Functions included in the IC chips may include GPS, RF, logic, and / or memory. The IC wafer 200 also includes intermediate metal interconnects and IC electrical contacts, which are typically bond pads. The IC electrical contacts are grouped into first and second contact sets 2228, 2230. The first set 2228 of IC contacts are designed to connect with MEMS electrical contacts associated with a first insulating path, and the second set 2230 are designed to connect with MEMS electrical contacts associated with a second insulating path.

[0055] Figure 2E is a schematic diagram of a multi-wafer stack 100 containing several single MEMS chips, such as MEMS chip 2100 of Figure 2A. The ASIC wafer 200 of Figure 2D and the MEMS multi-wafer stack 100 of Figure 2E can be fabricated in separate MEMS and IC foundries to minimize costs and increase yields using existing methods. In this example, two IC chips and two MEMS chips are shown before dicing.

[0056] During the fabrication of the MEMS stack 100, channels are etched into the first and second layers to define the boundaries of electrodes, leads, and feedthroughs on the inward-facing surfaces of the first and second silicon wafers. The channels are then covered or filled with an insulating material, such as thermal oxide or CVD (Chemical Vapor Deposition) silicon dioxide. Electrodes and MEMS structures, such as membranes and proof masses, are patterned on both sides of the central MEMS wafer, typically an SOI wafer. Conductive shunts are formed at specific locations within the buried oxide layer to allow electrical signals to pass from the device to the handle layer through what become insulating conductive paths. The central MEMS wafer and cap MEMS wafer are also patterned with respective frames that encapsulate the MEMS structures. The various conductive paths required by the devices are configured by aligning the feedthrough structures on each level. The portions of the insulating conductive paths in the central MEMS wafer can be isolated by insulator-filled channels or etched open trenches, since the MEMS wafers are fully contained within the stack and the insulating trenches do not need to provide a seal against atmospheric leakage as cap trenches do. A frame is also bonded to form a sealed chamber around the MEMS structure. After the wafer stack 100 is assembled, the cap wafer is ground and polished to expose the isolated conductive regions.

[0057] 2D-2F show a preferred method for bonding the MEMS wafer 100 and IC wafer 200. Underfill 44 is applied to the top CMOS wafer 200 and patterned to expose the IC electrical contacts (in this case, the bond pads). Solder bumps 45 are deposited on the bond pads. The IC wafer 200 is flipped over and aligned to the MEMS wafer 100 so that the IC bond pads and solder bumps are aligned with the bond pads of the first cap wafer. The IC wafer 200 is bonded to the MEMS wafer 100 using temperature and pressure to create a MEMS integrated system wafer.

[0058] The bonded 3DS wafers are then fabricated into 3D systems-on-chips (3DSoCs). to individual integrated MEMS system components, also known as systems on chips The diced 3DS component chip 2000 can be diced (along the dotted lines in FIG. 2F) with the diced IC chip 2000. The exposed side of the IC chip is protected by an oxide passivation layer applied to the silicon substrate, and the MEMS / ASIC contact areas are protected by underfill 44. The diced chip 2000, as shown in FIG. 2G, can be treated as a packaged IC, and the bottom cap bond pads provided on the second cap can be bump-bonded to bond pads on the PCB 300 without additional packaging. PCB underfill 44 is applied to the PCB and patterned to define contacts on the PCB bond pads. Solder bumps 45 are applied to the exposed PCB bond pads, and the diced 3DS component chip 2000 can be flip-chip bonded to the PCB 300. If additional moisture protection is desired, a polymer encapsulant or other material 34 can be applied. No additional capping or bond wires are required.

[0059] FIG. 3 is a block diagram illustrating one possible embodiment of an integrated MEMS system, in this case a 10-DOF IMU system 3000. System 3000 includes a 10-DOF single MEMS chip 3100 and a single IC chip 3200, with the MEMS chip and IC chip having architectures similar to those described for system 2000 of FIG. 2A. MEMS chip 3100 includes a top cap layer, a middle MEMS layer, and a bottom cap layer, with transducers patterned on each layer. The transducers may include a three-axis accelerometer, gyroscope, and magnetometer, as well as a pressure sensor. First and second insulating conductive paths 3130, 3150 are formed in the MEMS layers for transmitting MEMS signals and auxiliary signals. The insulating conductive paths 3130, 3150 connect to MEMS electrical contacts on the first and / or second cap layers. A single IC chip 3200 is bump-bonded to the first layer of the MEMS chip and includes MEMS signal processing circuitry 3240 and auxiliary processing circuitry 3260. The MEMS signal processing circuitry processes the transducer I / O signals, i.e., signals generated by and / or for controlling the transducers. The auxiliary processing circuitry 3260 processes auxiliary signals, i.e., signals that pass through the second isolated path of the MEMS chip 3100, such as digital signals for powering and / or controlling the transducers.

[0060] In this embodiment, MEMS signal processing circuit 3240 includes specialized digital CMOS circuit modules such as digital data analysis circuit 3242, digital input / output circuit 3244, memory 3246, system controller 3248, and calibration / compensation circuit 3250. Auxiliary signal processing circuit 3260 includes power management circuit 3262 and high-speed CMOS circuit 3264, which may include radio and / or GPS I / O modules. The digital components within MEMS signal processing circuit 3240 and auxiliary signal processing circuit 3260 communicate through digital bus 3272.

[0061] Because the converter operates using analog signals, IC chip 3200 includes mixed-signal CMOS circuitry 3270 to enable IC chip 3200 to interact with the inputs and outputs of MEMS sensor 3100. Mixed-signal CMOS circuitry 3270 includes an ADC to convert analog signals generated by MEMS chip 3100 into digital signals for processing by MEMS signal processing circuit 3240. Mixed-signal CMOS circuitry 3270 also includes a DAC to convert digital signals received from MEMS signal processing circuit 3240 and / or auxiliary signal processing circuit 3260 into analog signals for controlling MEMS chip 3100. Mixed-signal CMOS circuitry 3270 communicates with other digital components of IC chip 3200 through digital bus 3272.

[0062] The 3DS subsystem is distributed among these various circuits. For example, a 3DS Inertial Navigation Unit (ISU) based on a 10DOF MEMS sensor consisting of a 6DOF inertial sensor measuring angular velocity and acceleration, a pressure sensor, and a 3DOF magnetometer, as shown in Figure 3. Consider a NU (Inertial Navigation Unit). Part of a 3DS system can function as a system sensor hub when digital requests for position / orientation readings from the larger system come in through PCB board digital I / O leads or wireless I / O 3264, which requires high-speed CMOS or RF CMOS running at a higher clock rate than the memory or logic sections. Requests travel through digital bus 3272 and digital I / O section 3244 to system controller 3248. System controller 3248 provides clock signals to trigger and time the measurement of each of the three angular velocity, three acceleration, three magnetic field, and one pressure reading. Analog / digital section 3270 provides the DC bias and gyroscope drive signals needed to measure the capacitance of the various sensors, as well as amplifying and converting the signals into digital data representing angular velocity, acceleration, magnetic field, and pressure. The digital analysis circuit 3242 can acquire raw digital sensor data and, using algorithms and constants stored in memory 3246, can calculate real-time values of acceleration and angular velocity (IMU output), as well as pressure and magnetic field. However, if inertial navigation output (e.g., position and attitude) is required, the digital data analysis section 3242 performs additional calculations to integrate the 6DOF data with external sensor readings (such as GPS) and the pressure and magnetic field data to provide instantaneous position and attitude. These "sensor fusion" algorithms and constants can be stored in memory 3246. Ultimately, the results are output through the digital I / O section 3244 and digital bus, through the MEMS chip to the PCB board, or via RF wireless communication with the 3DS chip, which again acts as a sensor hub for communicating with a larger system.

[0063] As shown in the figure, IC 3200 interacts with MEMS chip 3100 via conductive paths 3130 and 3150. The first conductive path 3130 conducts transducer I / O signals and is therefore an analog channel. Therefore, first conductive path 3130 passes through a mixed-signal CMOS circuit 3270 interface before reaching digital bus 3272. The second conductive path 3150 conducts auxiliary signals. Because auxiliary signals can be analog or digital, they may take different paths into IC chip 3200 depending on their function. For example, analog auxiliary signals may interact with IC chip 3200 via mixed-signal CMOS circuit 3270, while digital signals may interact directly with digital bus 3272. When the second conductive path 3150 is carrying a power signal, for example, the second conductive path 3150 can function as a power bus 3274 and interact directly with the power management circuit 3262, which is also connected to the digital bus 3272 to convey digital data.

[0064] Referring to FIG. 4A, an alternative architecture for a MEMS integrated system allows multiple single MEMS wafers 102, 104 to be stacked vertically to form a 3DS MEMS wafer to reduce the final device footprint. FIG. 4A shows an IC wafer 202 bonded to a multi-wafer 3DS MEMS consisting of two MEMS wafers 102, 104 of different device types stacked and bonded together. By aligning the first and second insulating conductive paths (also called 3DTCVs), MEMS and auxiliary signals can be routed throughout the stack of MEMS and ASIC chips, simplifying power buses and minimizing lead routing between various MEMS functions and electronic devices. FIG. 4B shows a diced 3DS component 4000 consisting of an IC chip 4200 and a stack of two single MEMS chips 4102, 4104 bump-bonded to a printed circuit board 302. In this case, the second layer of the single MEMS chip 4102 is bump bonded to the first layer of the additional single MEMS chip 4104. The second insulating conductive paths 4150' of the additional single MEMS chip 4104 are at least partially bonded to the second insulating conductive paths 4150 of the first single MEMS chip 4102. The MEMS chips 4102 and 4104 are electrically connected to one another to conduct auxiliary signals through the first single MEMS chip and the additional single MEMS chip to auxiliary signal processing circuitry of the IC chip 4200. The interconnected second isolated conductive paths of the MEMS chips 4102 and 4104 allow the auxiliary signals to be transmitted from the PCB to the IC chip without the need for wire bonds.

[0065] MEMS signals for the MEMS chip 4104 can also pass through the MEMS chip 4102 to the IC chip 4200. The first MEMS chip 4102 includes a third set of first cap MEMS electrical contacts and third insulating conductive paths 4170 connecting the third set of first cap MEMS electrical contacts to at least some of the second cap MEMS electrical contacts of the second cap layer of the MEMS chip 4102 through the first cap layer, the central MEMS layer, and the second cap layer. These third insulating conductive paths 4170 are electrically connected to the MEMS signal processing circuitry 4240 of the IC chip 4200 and to the insulating conductive paths 4130′ of the MEMS chip 4104. Thus, the MEMS signal processing circuitry 4240 can process electrical MEMS signals of the first single MEMS chip and the at least one additional single MEMS chip. Thus, the MEMS signal processing circuit 4240 can process MEMS signals from both MEMS chips 4102 and 4104 .

[0066] 4A and 4B, there are two MEMS chips, but it is of course possible to stack three or more MEMS chips of the same or different types. Thus, an integrated MEMS system component may include a first single MEMS chip and additional single MEMS chips stacked vertically.

[0067] 5A and 5B, when the variations in IC types are too complex to accommodate with a single ASIC (e.g., mixed-signal functions plus GPS functions plus radio frequency (RF) functions), the MEMS wafer stack 106 can be used as a 3DS substrate containing a first IC chip for processing MEMS signals and auxiliary signals and additional IC chips 5204, 5206, 5208 of desired types, such as GPS, RF, logic, processors, memory, etc., and bump-bonded to one of the cap wafers of the multi-wafer stack 106. Rather than using wafer bonding to attach the single ASIC wafer to the MEMS wafer stack, as in FIG. 5A, PCB chip attachment methods such as pick-and-place and solder bump attachment are used to align and bond the IC bond pads and MEMS solder bumps. Thus, each IC chip is individually placed and bonded to the MEMS wafer to form a 3D System Wafer (3DS wafer), which is then singulated into individual 3D System in Package (3DSiP) chips.

[0068] 5B, the MEMS metal layer 38 in this case serves not only to connect the MEMS chip 5106 to the various ICs 5204, 5206, 5208, but also to interconnect the ICs and provide signal and power distribution thereto. In any event, after dicing, the individual 3DS components 5000 can be treated as completed system chips without additional packaging or wire bonding. The system chip 5000 can be bump bonded to the PC board 304.

[0069] The scope of the claims should not be limited by the preferred embodiments set forth in each example, but should be accorded the broadest interpretation consistent with the description as a whole.

Claims

1. 1. An integrated MEMS system comprising: at least one single MEMS chip, and at least one single IC chip Equipped with the at least one single MEMS chip; a first cap layer including a first and a second set of first cap MEMS electrical contacts; a second cap layer including a second cap MEMS electrical contact; a central MEMS layer arranged between said first cap layer and said second cap layer; at least one transducer formed in said first cap layer, said central MEMS layer and said second cap layer to induce motion or sense at least one parameter; - first insulating conductive paths connecting said at least one transducer to a first set of said first cap MEMS electrical contacts respectively to conduct electrical MEMS signals between said at least one transducer and said first set of said first cap MEMS electrical contacts; - second insulating conductive paths connecting a second set of the first cap MEMS electrical contacts to at least some of the second cap MEMS electrical contacts through the first cap layer, the central MEMS layer and the second cap layer to conduct auxiliary signals through the MEMS chip; Equipped with the at least one single IC chip: - first and second sets of IC electrical contacts bump-bonded to the first and second sets of first cap MEMS electrical contacts, respectively; a MEMS signal processing circuit operatively connected to the first set of IC electrical contacts for processing said electrical MEMS signals; an auxiliary signal processing circuit operatively connected to a second set of said IC electrical contacts for processing said auxiliary signals and providing additional system functionality; An integrated MEMS system comprising:

2. 10. The integrated MEMS system of claim 1, wherein the first cap layer, the central MEMS layer, and the second cap layer are made of a conductive material, the first cap layer is electrically bonded to a first side of the central MEMS layer, and the second cap layer is electrically bonded to a second side of the central MEMS layer opposite the first side.

3. 3. The integrated MEMS system of claim 1 or 2, wherein the first cap layer, the central MEMS layer, and the second cap layer are fabricated from respective silicon-based wafers that are bonded at the wafer level.

4. 4. An integrated MEMS system according to any one of claims 1 to 3, wherein the central MEMS layer is made from a silicon-on-insulator wafer.

5. 5. The integrated MEMS system of claim 1, wherein the second insulating conductive paths are formed by trenches etched in one of the first layer, the central MEMS layer, and the second layer, the trenches being aligned and filled with an insulating material, the trenches surrounding respective conductive wafer plugs; An integrated MEMS system, wherein the conductive wafer plug allows transmission of electrical signals through the entire thickness of the MEMS chip.

6. 6. An integrated MEMS system according to claim 1, wherein at least some of the second insulating conductive paths are formed by trenches etched in one of the first layer, the central MEMS layer and the second layer, the trenches being aligned and having their respective sidewalls lined with an insulating material and filled with a conductive material.

7. 7. The integrated MEMS system of claim 1, wherein the first and second cap MEMS electrical contacts of the first and second cap layers are bond pads.

8. 8. An integrated MEMS system according to claim 1, wherein the at least one transducer comprises a six-degree-of-freedom motion sensor, and the at least one parameter comprises three axes of linear acceleration and three axes of angular velocity.

9. 10. The integrated MEMS system of claim 9, wherein the six degrees of freedom motion sensor includes first and second sets of electrodes provided in the first and second cap layers, respectively, and a plurality of proof masses provided in the central MEMS layer, the first and second sets of electrodes forming capacitors with the plurality of proof masses, and some of the first insulating conductive paths respectively connecting the electrodes of the first and second sets of electrodes to at least some of the first cap MEMS electrical contacts of the first set of MEMS electrical contacts.

10. 10. An integrated MEMS system according to any one of claims 1 to 9, wherein the at least one transducer comprises at least one non-inertial sensor.

11. 11. The integrated MEMS system of claim 10, wherein the at least one non-inertial sensor comprises at least one of a pressure sensor, a magnetometer, a thermometer, and a microphone.

12. 12. An integrated MEMS system as described in claim 10 or 11, wherein the at least one non-inertial sensor includes a non-inertial electrode patterned in the first layer and at least one MEMS structure patterned in the central MEMS layer, and some of the first insulating conductive paths connect the electrodes of the at least one non-inertial sensor to at least some of the first set of first cap MEMS electrical contacts.

13. 13. An integrated MEMS system according to any one of claims 1 to 12, wherein at least some of the electrical MEMS signals are analog signals, and wherein the IC chip includes mixed-signal CMOS circuitry for converting analog signals transmitted by the MEMS chip into digital signals for processing by the MEMS signal processing circuitry, and for converting digital signals transmitted by the MEMS signal processing circuitry into analog signals before entering the MEMS chip.

14. 14. An integrated MEMS system according to any one of claims 1 to 13, wherein the IC chip includes a digital bus, and the MEMS signal processing circuitry includes a digital CMOS circuit connected to the mixed signal circuitry via the digital bus.

15. 15. The integrated MEMS system of claim 14, wherein the digital CMOS circuitry includes at least one of digital data analysis circuitry, digital input / output circuitry, memory, a system controller, and calibration / compensation circuitry.

16. 16. An integrated MEMS system according to claim 14 or 15, wherein the IC chip includes a power bus, and the auxiliary signal processing circuitry includes a power management circuit connected to the power bus and the digital bus.

17. 17. An integrated MEMS system according to any one of claims 14 to 16, wherein the IC chip includes high speed CMOS circuitry connected to the digital bus for processing the auxiliary signals.

18. 20. The integrated MEMS system of claim 17, wherein the high speed CMOS circuitry includes at least one of an input / output module for radio signals or GPS signals.

19. 19. The integrated MEMS system of claim 1, wherein the at least one single MEMS chip includes a first single MEMS chip and at least one additional single MEMS chip, the first single MEMS chip and the at least one additional single MEMS chip being vertically stacked, the second layer of the first single MEMS chip being bump-bonded to the first layer of the at least one additional single MEMS chip, and the second insulating conductive paths of the at least one additional single MEMS chip being electrically connected to at least some of the second insulating conductive paths of the first single MEMS chip to conduct auxiliary signals through the first single MEMS chip and the at least one additional single MEMS chip to the at least one IC chip.

20. 20. The integrated MEMS system of claim 19, wherein a first MEMS chip includes a third set of first cap MEMS electrical contacts and third insulating conductive paths connecting the third set of first cap MEMS electrical contacts to at least some of the second cap MEMS electrical contacts through the first cap layer, the central MEMS layer, and the second cap layer, the third insulating conductive paths being electrically connected to the MEMS signal processing circuitry of the at least one IC chip and to the insulating conductive paths of the at least one additional single MEMS chip, and the MEMS signal processing circuitry processes the electrical MEMS signals of the first single MEMS chip and the at least one additional single MEMS chip.

21. 21. An integrated MEMS system according to any one of claims 1 to 20, wherein the at least one single MEMS chip comprises a first single IC chip and at least one additional single IC chip.

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