Soc PMUT, array chip and manufacturing method suitable for high-density system integration

Abstract

The invention discloses a SOC PMUT suitable for high-density system integration, an array chip and a manufacturing method. The SOC PMUT suitable for high-density system integration is directly bonded to an active wafer, and has a multi-channel metal wiring structure in a vertical direction. Realize the vertical stacking of SOC PMUT array and its CMOS auxiliary circuit, monolithic integration, and extend to the packaging level through TSV, no longer need to communicate with CMOS through the pads around the array, and relieve the metal interconnection of traditional ultrasonic transducers The bottleneck greatly reduces the chip area occupied by the metal interconnection of the ultrasonic transducer, and at the same time reduces the length of the metal wiring, and the resulting electrical parasitic effects have a negative impact on the performance of the ultrasonic transducer array.

Description

technical field [0001] The invention relates to the technical field of high-density single-chip integrated semiconductor sensors, in particular to a new structure and processing technology for integrating a 3D (3dimensional) three-dimensional PMUT framework and an SOC (System-On-Chip). Background technique [0002] Ultrasonic diagnostic instrument, through its ultrasonic probe, emits ultrasonic waves to the human body, and uses various information generated by the reflection, refraction, and diffraction of sound during the propagation process of human organs and tissues to receive, amplify, and transmit information. processed to form an image or flow Doppler and finally displayed on a monitor. A medical color ultrasonic diagnostic instrument mainly includes: probe, host, control panel, display and other accessories. [0003] As human society enters the era of big medical care, the application of medical ultrasound has developed rapidly. From medical imaging, such as fetal ...

AI Technical Summary

Problems solved by technology

As a result, metal routing faces two major constraints

First, if you want each cell to have its own independent top-level metal connection, as shown in Figure 2(b), you must add an additional amount of metal routing

As a result, the metal wiring reduces the duty cycle of the PMUT unit (the ratio of the area that can generate ultrasound in the unit to the entire unit area), and the metal wiring takes up a large proportion of the chip area outside the array at the same time, and the parasitics generated by the additional metal wiring Resistors, Capacitors, have adverse effects on speed, power consumption, etc.

Second, the design of most PMUT arrays today, in order to reduce additional metal wiring, shares the same top-level metal connection (common column connection) with multiple cells in the same column. As a result, the mutual interference (cross-talk) of these cells becomes serious, the main performance parameters of the PMUT array, such as effective frequency bandwidth, signal-to-noise ratio, etc., are adversely affected

The chip area occupied by the metal wiring is much larger than the chip area occupied by the PMUT array, which is extremely uneconomical

At the same time, the longer metal wiring length increases the parasitic effect of resistors and capacitors, which has a negative impact on the operating frequency and power consumption of the PMUT array.

The uneven length of the wiring will also directly affect the uniformity of the work of the PMUT array

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