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

Abstract

The invention discloses an SOC PMUT suitable for high-density system integration, an array chip and a manufacturing method. The SOC PMUT suitable for high-density system integration realizes vertical stacking and monolithic integration of an SOC PMUT array and a CMOS auxiliary circuit thereof through direct bonding of an active wafer and a multi-channel metal wire structure in the vertical direction, and extends to a packaging layer through a TSV, so that the SOC PMUT does not need to be communicated with a CMOS through pressure welding blocks on the periphery of the array, the bottleneck of traditional ultrasonic transducer metal interconnection is relieved, the chip area occupied by the ultrasonic transducer metal interconnection is greatly reduced, meanwhile, the length of metal wiring is reduced, and the bad influence of the electrical parasitic effect caused by the length on the performance of an ultrasonic transducer array is reduced.

Description

technical field [0001] The invention relates to the technical field of high-density single-chip integrated semiconductor sensors, and specifically relates to a new structure and processing technology for the integration of 3D (3dimensional) three-dimensional PMUT architecture and 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...

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 also occupies a large proportion of the chip area outside the array, and the parasitics generated by the additional metal wiring Resistors, Capacitors, have adverse effects on speed, power consumption, etc.

Second, most of today's PMUT array designs, in order to reduce additional metal wiring, share the same top-level metal connection (common column connection) with multiple cells in the same column. As a result, these cells interfere with each other (cross-talk) 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

Images