An optoelectronic mechanism multi-dimensional force sensing array device integrated with logic operation function on chip and a preparation method thereof

Abstract

The application belongs to the field of semiconductor mechanical sensors, and discloses a preparation method of a photoelectric mechanism multi-dimensional force sensing array integrated with a logic operation function on a chip, which comprises an optical chip integrated with light emitting, light sensing and logic operation functions on a chip and flexible light guide material preparation. The optical chip internally comprises a plurality of optical device units integrated in an array on a single chip, each unit internally comprising a plurality of light emitting and light sensing devices, which are connected through designed electrodes to realize series / parallel connection of the plurality of light sensing devices integrated on the chip, and thus realize logic operation of an output photoelectric current signal. Through the light emitting, light sensing and logic operation functions of the optical sensing array integrated on the chip, miniaturization of the multi-dimensional force sensing module can be realized.

Description

Technical Field

[0001] This invention relates to the field of semiconductor mechanical sensors, and more specifically to a photoelectric sensing mechanism and integration method. Background Technology

[0002] Multidimensional mechanical detection technology, as a core means of perceiving object shape, determining surface contact state, and monitoring slippage, has significant application value in fields such as precision robot control, intelligent human-computer interaction, and advanced medical equipment. Particularly in minimally invasive surgical robots and precision assembly systems, the deployment of high-resolution multidimensional force sensor arrays plays a crucial role in achieving real-time analysis of multidimensional force feedback. This allows the mechanical system to dynamically perceive the spatial force distribution during interaction, thereby constructing an adaptive intelligent response mechanism.

[0003] Existing multidimensional force detection systems mainly encompass three types of sensing schemes: capacitive, resistive, and optical. Among them, optical sensing technology, with its significant advantage of millinewton-level detection limit, exhibits superior characteristics in terms of resolution. A typical optical sensing module achieves mechanical sensing by constructing an optical path system consisting of a light source, an elastic reflective interface, and a photodetector: when an external force acts on the elastic body, causing interface deformation, the reflected light path of the light emitted by the light source changes accordingly, and the photodetector inverts the three-dimensional force vector information by analyzing the change in light intensity distribution. However, traditional optical sensors are constrained by the physical configuration of discrete light sources, detectors, and logic circuits (used to process output signals). The spatial arrangement requirements of discrete optical devices and logic circuits severely restrict the miniaturization process of the entire system, making high-density array integration difficult to achieve. Although some researchers have proposed integrating discrete light sources and detectors on a single chip to achieve miniaturization of a single force sensing unit, and packaging multiple force sensing units on a printed circuit board (PCB) to achieve board-level sensing and computing integration, there are currently no chip-level three-dimensional force sensing array integration or chip-level three-dimensional force sensing and computing integrated solutions. Summary of the Invention

[0004] To address the shortcomings of the existing technologies, this invention provides a photoelectric mechanism multidimensional force sensing array with on-chip integrated logic operation functions. This integrates the light emission, light sensing, and logic operation functions of the photoelectric sensing array into a single chip, achieving miniaturized integration of the entire multidimensional force sensing array module and helping to overcome size limitations in many application scenarios.

[0005] The present invention adopts the following technical solution:

[0006] A method for fabricating a photoelectric mechanism multidimensional force sensing array with on-chip integrated logic operation functions includes the fabrication of an optical chip with on-chip integrated light emission, light sensing, and logic operation functions, and a flexible light guide material, comprising the following fabrication steps:

[0007] (1) On an epitaxial wafer with an LED epitaxial structure, an n-type region is exposed by photolithography and etching;

[0008] (2) The substrate is exposed by photolithography and etching to form electrical isolation between various optical devices in the optical chip;

[0009] (3) Photolithography followed by vapor deposition of p / n interdigitated electrode layers;

[0010] (4) Deposition of passivation protective layer;

[0011] (5) Using photoresist as a mask, passivation protection layer openings are formed by etching, interconnect electrode layers are deposited by vapor deposition, and optical chips are fabricated.

[0012] (6) Fix a flexible light guide material with reflective and refractive contact surfaces onto the optical chip.

[0013] The optical chip contains multiple optical device units integrated on a single array, and each unit contains several light-emitting and photosensitive devices.

[0014] The light-emitting and photosensitive devices within the optical device unit have the same epitaxial structure.

[0015] By designing the interconnect electrode layer described in step (5), multiple on-chip integrated photosensitive devices can be connected in series / parallel, thereby enabling basic logic operations such as AND, OR, NAND, and NOR of the output photocurrent signal, as well as more combinational logic operations.

[0016] Optionally, electrical isolation is formed between the optical device units within the optical chip and between the devices within the optical device units by etching to the substrate and depositing a passivation protective layer.

[0017] Optionally, the transparent substrate of the optical chip may be made of sapphire.

[0018] Optionally, the epitaxial material of the optical chip includes GaN, InGaN, AlGaN, or InP, GaAs material systems, etc.

[0019] When the flexible light guide material described in step (6) is subjected to an external force, it deforms, thus changing the contact surface with the optical chip and altering the optical path within the chip. This causes the photosensitive device within the optical device unit of the chip to generate an output signal jump. The contact surface between the flexible light guide material and the optical chip includes a reflective surface and a refractive surface. When these two surfaces come into contact with the optical chip, they respectively cause opposite output photocurrent signal jumps.

[0020] Optionally, the flexible light guide material forms a partial reflective surface by attaching a metal sheet.

[0021] Optionally, the flexible light guide material includes polydimethylsiloxane (PDMS).

[0022] Optionally, the flexible light guide material is 3D printed into a mold, and a prepolymer and curing agent are poured into the mold and heated to cure it into the desired shape.

[0023] Optionally, the flexible light guide material is fixed to the surface of the optical chip substrate with adhesive.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] This invention provides a feasible solution for miniaturizing and integrating a high-precision three-dimensional force sensing array module, integrating a high spatial resolution three-dimensional mechanical sensor array with logic operation functions into a single chip. This technical solution has significant advantages in reducing the overall size of the three-dimensional force sensing array and improving spatial resolution. Attached Figure Description

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0027] Figure 1 This is a schematic diagram of the structure of an optical chip provided in an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the optical device unit within the optical chip provided in an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the combination of an optical chip and a flexible light guide material provided in an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram illustrating the working principle of the multi-dimensional force sensing unit provided in an embodiment of the present invention. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0032] Figure 1 This is a schematic diagram of the optical chip structure required for a photoelectric mechanism multi-dimensional force sensing array device with on-chip integrated logic operation function provided in an embodiment of the present invention. The diagram includes a light-emitting device (in the middle) and two photosensitive devices (on both sides) in the optical device unit. Figure 1As shown, the optical chip includes: a sapphire substrate 01, an n-type gallium nitride layer 02, a quantum well layer 03, a p-type gallium nitride layer 04, an indium tin oxide layer 05, a p / n interpolation electrode layer 06, a silicon dioxide passivation protection layer 07, a distributed Bragg reflector layer 08, and an interconnect electrode layer 09.

[0033] The optical chip in this embodiment is specifically prepared by the following method:

[0034] (1) Clean the sapphire substrate epitaxial wafer on which p-type gallium nitride layer 04, quantum well layer 03 and n-type gallium nitride layer 02 have been epitaxially grown;

[0035] (2) Deposit an indium tin oxide layer 05 and expose a portion of the n-type gallium nitride layer 02 by photolithography and etching;

[0036] (3) The sapphire substrate 01 is exposed by photolithography and deep dry etching to form electrical isolation between optical device units within the optical chip, as well as electrical isolation between independent devices within the optical device unit.

[0037] (4) After photolithography, the p / n interdigitated electrode layer 06 is prepared by electron beam evaporation;

[0038] (5) Deposit a silicon dioxide passivation protective layer 07 and a distributed Bragg reflector layer 08;

[0039] (6) Using photoresist as a mask, passivation layer openings are formed by dry etching, and interconnect electrode layer 09 is deposited by vapor deposition, forming a connection with interdigitated electrode layer 06. By designing the wiring of interconnect electrode layer 09, electrical interconnections between each sensing unit are formed, and logic gate circuits can be constructed.

[0040] Figure 2 This is a schematic diagram of a single optical device unit 30 within an optical chip provided in an embodiment of the present invention. For ease of explanation, Figure 2 Midsection I and Figure 1 The device structure shown corresponds to the diagram. The diagram contains nine independent, mutually insulated devices: photosensitive devices 11-18 and light-emitting device 19. The area between the devices is a silicon dioxide passivation protective layer 07.

[0041] Figure 3 This is a schematic diagram of the combination of optical chip 10 and flexible light guide material (PDMS) 20 provided in an embodiment of the present invention. The optical chip 10 contains 3×3 optical device units 30.

[0042] Figure 4 for Figure 3 The supplementary diagram illustrates the working principle of the multi-dimensional force sensing unit. It is worth noting that in this embodiment, each optical device unit and the PDMS material above form force sensing units in different directions, and the resulting sensing structures are as follows: Figure 4 (a) or Figure 4 (c) One type is used to sense horizontal or vertical forces. A force in a specific direction causes deformation of the thin film, thus changing the contact material on the outer surface of the sapphire: when switched from air to PDMS, total internal reflection at the interface decreases, reducing the amount of light received by the photosensitive device; when switched from air to a metallic reflective layer, the amount of light received by the photosensitive device increases. Figure 4 It is known that the photocurrent within the photosensitive devices in the two types of sensing units changes when tangential and axial forces are applied, and the photosensitive devices on both sides generate signal transitions in opposite directions. For example, for the left-direction force sensing unit, when a leftward thrust is applied, the photocurrent of the left-side photosensitive device decreases, while the photocurrent of the right-side photosensitive device increases; for the downward force sensing unit, when a downward pressure is applied, the photocurrent of the left-side photosensitive device increases, while the photocurrent of the right-side photosensitive device decreases. This phenomenon of generating opposite photocurrent signal transitions for the same input force signal helps to realize on-chip NOT logic operations. By connecting the photosensitive devices in different optoelectronic device units in series or parallel, AND, OR, NAND, and NOR logic operations between different force measurement units can be realized.

[0043] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A method for fabricating a photoelectric multidimensional force sensing array device with on-chip integrated logic operation functions, comprising the fabrication of an optical chip with on-chip integrated light emission, light sensing, and logic operation functions, and a flexible light guide material, characterized in that: (1) On an epitaxial wafer with an LED epitaxial structure, an n-type region is exposed by photolithography and etching; (2) The substrate is exposed by photolithography and etching to form electrical isolation between various optical devices in the optical chip; (3) Photolithography followed by vapor deposition of p / n interdigitated electrodes; (4) Deposition of passivation protective layer; (5) Using photoresist as a mask, passivation layer openings are formed by etching, and interconnect electrode layers are deposited by vapor deposition to fabricate an optical chip; (6) Fix a flexible light guide material with reflective and refractive contact surfaces onto the optical chip.

2. The method for fabricating the optoelectronic multidimensional force sensing array device with on-chip integrated logic operation function according to claim 1, characterized in that, The optical chip contains multiple optical device units integrated on a single array. Each unit contains several light-emitting and photosensitive devices, and the light-emitting and photosensitive devices have the same epitaxial structure.

3. The method for fabricating the optoelectronic multidimensional force sensing array device with on-chip integrated logic operation function according to any one of claims 1-2, characterized in that, By designing electrode connections, multiple on-chip integrated photosensitive devices can be connected in series or parallel, thereby enabling basic logic operations such as AND, OR, NAND, and NOR of the output photocurrent signal, as well as more combinational logic operations.

4. The method for fabricating the optoelectronic multidimensional force sensing array device with on-chip integrated logic operation function according to claim 3, characterized in that, Electrical isolation is formed between the optical device units within the optical chip and between the devices within the optical device units through etching to the substrate and deposition of a passivation protective layer.

5. The method for fabricating the optoelectronic multidimensional force sensing array device with on-chip integrated logic operation function according to claim 1, characterized in that, The epitaxial substrate is a transparent substrate.

6. The method for fabricating the optoelectronic multidimensional force sensing array device with on-chip integrated logic operation function according to claim 1, characterized in that, The contact surface between the flexible light guide material and the optical chip includes a reflective surface and a refractive surface. When these two surfaces come into contact with the optical chip, they respectively cause opposite output photocurrent signal jumps.

7. The method for fabricating the optoelectronic multidimensional force sensing array device with on-chip integrated logic operation function according to claim 1, characterized in that, When the flexible light guide material is subjected to an external force, it deforms, thus changing the contact surface with the optical chip and altering the optical path within the chip, causing the photosensitive device in the optical device unit within the chip to generate an output signal jump.

8. The method for fabricating the optoelectronic multidimensional force sensing array device with on-chip integrated logic operation function according to claim 1, characterized in that, The flexible light guide material is fixed above the substrate surface of the optical chip.

9. A photoelectric mechanism multidimensional force sensing array device with on-chip integrated logic operation function, characterized in that, It is prepared by the preparation method according to any one of claims 1-8.

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