CN103035656B - A kind of optical sensor system based on CMOS processing technology - Google Patents

Abstract

The invention provides a kind of optical sensor system based on CMOS processing technology, comprise the integrated computing circuit being arranged on the optical sensor on cmos circuit plate and being connected with optical sensor, described optical sensor is formed by sensing unit array, described sensing unit comprises diffraction grating, analyze grating and PN junction array, the vertical range analyzed between grating and diffraction grating is that the m/n of distance protects doubly in diffraction grating Thailand, m and n is positive integer, described analysis grating forms dislocation to described diffraction grating at a certain distance and blocks, achieve the detection of the angle information to planar light thus easily, thus extend the function application of optical sensor system, technological design is simple, be suitable for extensive industrialization to make.

Description

A kind of optical sensor system based on CMOS processing technology

[technical field]

The present invention relates to light sensing and optical communication field, relate to a kind of optical sensor system based on CMOS processing technology particularly.

[background technology]

Over nearly 30 years, semi-conductor industry follows Moore's Law development always and, and as one of the basis of semi-conductor industry, semiconductor process techniques is also at development and improvement increasingly.After middle 1960s cmos device invention, it is fast-developing that CMOS technology just starts considerable ground, CMOS technology grows up on PMOS and NMOS Process ba-sis, nmos device and PMOS device are arranged on same silicon substrate simultaneously and make CMOS integrated circuit, the most basic technique of CMOS has: the silicon wafer technique of producing required type substrates; Determine the photoetching process of machining area; The oxidation of material, deposit, diffusion and ion implantation technology is increased in chip; Remove the etching technics of the material on chip; The manufacture of integrated circuit is made up of the various combination of these fundamental technologies.

Along with the fast development of semiconductor process techniques especially CMOS technology technology, on one single chip, the quantity of transistor is just becoming geometric progression constantly to increase, and this scaled trend of chip makes chip while Highgrade integration, have more, more complicated function.Since the nineties in 20th century, the chip manufacturing process of integrated circuit, microprocessor has entered into the system single chip epoch of " nanoelectronic level " from " micron order ", " deep-submicron ", on a CMOS integrated chip, integratedly can comprise CPU, DSP, logical circuit, analog circuit, radio circuit, memory and other circuit module and embedded software etc., and be interconnected to constitute complete system.

In recent years, as a member very important in sensor technology, optical sensing obtains significant progress in many applications, and current various optical sensor is widely used in industry-by-industry.So-called optical sensor is exactly take light as detected object what is called optical sensor is exactly take light as detected object, light signal is converted to the device of the signal of telecommunication, typically refer to the transducer of ultraviolet to infrared wavelength range, it is the detector utilizing the photoelectric effect of material to make, therefore also referred to as optical-electrical converter.Due to optical sensing have highly sensitive, volume is little, anti-electromagnetic interference capability is strong, it is integrated to be convenient to, can the many merits such as on-line checkingi, current photo-sensing device is widely used and develops in the every field such as optical communication, environmental monitoring.Current optical sensor mainly contains based on several types such as optical fiber, grating and planar optical waveguides, pass through CMOS technology, optical sensor can be integrated on CMOS integrated chip, by integrated logical circuit and computing circuit etc., the signal of telecommunication that can export optical sensor calculates the strength information of planar light, and then obtains information to be measured.But existing optical sensor is difficult to the photoelectric properties of integrated complex simultaneously at one chip, to realize the detection to light signal strength information and angle information simultaneously.

[summary of the invention]

The present invention, for solving the problems of the technologies described above, provides a kind of optical sensor system based on CMOS processing technology.

The technical scheme that the present invention realizes goal of the invention employing is: a kind of optical sensor system based on CMOS processing technology, comprise the integrated computing circuit being arranged on the optical sensor on cmos circuit plate and being connected with optical sensor, described optical sensor is formed by sensing unit array, described sensing unit comprises diffraction grating, analyze grating and PN junction array, described diffraction grating and analysis grating are the metal wiring layer of dual-layer Parallel vibrational power flow at described circuit board, described analysis parallel gratings is arranged on the below of described diffraction grating, the vertical range analyzed between grating and diffraction grating is that the m/n of distance protects doubly in diffraction grating Thailand, m and n is positive integer, described analysis grating forms dislocation to described diffraction grating at a certain distance and blocks, described PN junction array is positioned at the below of described analysis grating and is arranged at the layer-of-substrate silicon of described cmos circuit plate.

Preferably, the diffraction grating of described sensing unit is mutually vertical between two forms sensing unit pair.

Preferably, the vertical range between described analysis grating and described diffraction grating is that distance is protected by 1/2 times of diffraction grating Thailand.

Preferably, corresponding to each PN junction, described analysis grating intermediate reach one is blocked grating width to increase D/N, D be the pitch of described diffraction grating, N be more than or equal to 2 integer, form described analysis grating and at a certain distance dislocation formed to described diffraction grating and block.

Preferably, corresponding to each PN junction, at described analysis grating intermediate reach, the width in a grating space is increased the pitch that D/N, D are described diffraction grating, N be more than or equal to 2 integer, form described analysis grating and at a certain distance dislocation formed to described diffraction grating and block.

Preferably, described N is more than or equal to 4.

Preferably, described computing circuit be made up of CMOS adder, subtracter, divider and arctangent cp cp operation circuit the anti-computing circuit releasing plane angular information is calculated to the signal that described PN junction array exports.

The invention has the beneficial effects as follows: based on CMOS technology, integrated in cmos circuit plate a planar light transducer is set, the detection to the angle information of planar light is realized by the sensing unit be made up of diffraction grating, analysis grating and PN junction array, thus extend the function application of optical sensor system, and technological design is simple, is suitable for extensive industrialization and makes.

[accompanying drawing explanation]

Fig. 1, the plan view of planar light transducer.

The zoomed-in view that in Fig. 2, Fig. 1, sensing unit is right.

Fig. 3, embodiment 1 is based on the sensing unit structures schematic diagram of CMOS technology.

Fig. 4, embodiment 2 is based on the sensing unit structures schematic diagram of CMOS technology.

[embodiment]

Below in conjunction with accompanying drawing, the present invention is described in detail.

A kind of optical sensor system based on CMOS processing technology, comprise the integrated computing circuit being arranged on the planar light transducer on cmos circuit plate and being connected with planar light transducer, planar light transducer is formed by sensing unit pair array, sensing unit forms by two identical sensing units 100, figure 1 show by the plan view of multiple sensing unit to the planar light transducer that I forms, in figure, I represents sensing unit pair.Figure 2 illustrate the zoomed-in view that sensing unit is right, in figure, the diffraction grating 101 in two sensing units 100 is mutually vertical.

Embodiment 1:

Figure 3 show the sensing unit structures schematic diagram of embodiment 1 based on CMOS technology, sensing unit 100 is by diffraction grating 101, analysis grating 102 and PN junction array 103 form, diffraction grating 101 and analysis grating 102 are that dual-layer Parallel vibrational power flow is in the metal wiring layer of cmos circuit plate, analyze the below that grating 102 is set in parallel in diffraction grating 101, the parallel distance analyzed between grating 102 and diffraction grating 101 is that distance is protected by 1/2 times of diffraction grating Thailand, 4 PN junction composition PN junction arrays 103 are positioned at the below the layer-of-substrate silicon 200 being arranged at cmos circuit plate of analyzing grating 102, corresponding to each PN junction, 1/4D is increased at the width one being blocked with analyzing grating 102 intermediate reach grating 104, D is the pitch of diffraction grating 101, formed and analyze grating 102 with 1/4D, 1/2D, 3/4D, the distance of D forms dislocation to diffraction grating 101 and blocks.

Wherein, diffraction grating 101 is according to designing with Talbot effect (Talbot effect), its content can be summarized as: when periodic light signal is irradiated on diffraction grating 101, its picture can repeat in the position of a series of multiple of fixed range from diffraction grating 101, and this fixed range is just called safe distance (Talbot length) of protecting, these pictures are called as protects picture (Talbot Image) from imaging (Self Image) or Thailand.The principle that the present invention utilizes Talbot effect (Talbot effect) to detect the incident angle of light is: when the incidence angle of light changes, diffraction grating 101 can there is transverse shifting from imaging (Self Image), and the degree of depth of imaging does not have obvious change.Therefore, by measuring these transverse shifting degree, we just can extract the angle information of incident light.In order to extract these transverse shifting information, the present invention addition of a layer analysis grating 102 (additional analyzer grating) in the lower floor of diffraction grating 101 (diffraction grating), analyze grating 102 according to a mole effect (moire effect) affect diffraction grating from imaging (Self Image): when being on same straight line from the intensity peak of imaging and the printing opacity analyzing grating 102, so light signal just shines directly on the PN junction array analyzed under grating 102; When from the intensity peak of imaging with analyze the printing opacity place of grating 102 not on same straight line, light signal just can block by analyzed grating 102 to some extent.

Like this, by addition of a layer analysis grating 102, just making the luminous intensity at diverse location place under two-layer optical grating construction produce different, and in these strength informations, containing the angle information of incident light; Then we arrange that optoelectronic induction array obtains different luminous intensity responses to make them over these locations, and in these intensity response, contain the angle information of light, by carrying out calculation process to the luminous intensity response of diverse location PN junction, the incident angle of light just instead can be released.At present, most photovoltaic sensing element is all the photoelectric device utilizing illumination to penetrate PN junction generation photoelectric current and make, in PN junction array 103, PN junction is in reverse-bias state, when incident intensity changes, can there is respective change in the concentration of the electron-hole produced near PN junction, thus change the concentration of minority carrier, finally makes photo-current intensity change.

The output response of 4 PN junction arrays 103 can be described with following formula:

V0＝I0(1-mcos(bθ))F(θ) (1)

V1＝I0(1+msin(bθ))F(θ)) (2)

V2＝I0(1+mcos(bθ))F(θ)) (3)

V3＝I0(1-msin(bθ))F(θ)) (4)

Wherein, θ represents angle of light degree, m and b is coefficient of angularity, and F (θ) represents optical surface reflective information, and V0, V1, V2, V3 represent the output response at diverse location place; I0 represents luminous intensity.

By formula (1)-(4), the computing circuit be made up of CMOS adder, subtracter, divider and arctangent cp cp operation circuit calculates the signal that described PN junction array exports, and can instead easily release:

$\mathrm{\θ}={\tan }^{-1}\left(\frac{V2-V0}{V3-V1}\right)$

Embodiment 2:

Fig. 4 illustrate the sensing unit structures schematic diagram of embodiment 2 based on CMOS technology, sensing unit 100 is by diffraction grating 101, analysis grating 102 and PN junction array 103 form, described diffraction grating 101 and analysis grating 102 are that dual-layer Parallel vibrational power flow is in the metal wiring layer of cmos circuit plate, analyze the below that grating 102 is set in parallel in diffraction grating 101, the parallel distance analyzed between grating 102 and diffraction grating 101 is that distance is protected by diffraction grating Thailand, 4 PN junction composition PN junction arrays 103 are positioned at the below the layer-of-substrate silicon 200 being arranged at cmos circuit plate of analyzing grating 102, corresponding to each PN junction, at analysis grating 102 intermediate reach, the width in a grating space 105 is increased 1/4D, D is the pitch of diffraction grating 101, formed and analyze grating 102 with 1/4D, 1/2D, 3/4D, the distance of D forms dislocation to diffraction grating 101 and blocks.

The principle of embodiment 2 is identical with embodiment 1, no longer repeats at this.

Should be understood that: when the PN junction number forming PN junction array 103 is 2,3 or other are greater than arbitrarily the integer of 2, still can releases angle of light degree θ by light signal response formula is counter, only need more complex calculations process.

Should be understood that: analyze vertical range between grating 102 and diffraction grating 101 can for safe protect any m/n times of distance time (m, n are positive integer).

As shown in the above description, based on CMOS technology, integrated in cmos circuit plate a planar light transducer is set, the detection to the angle information of planar light is realized by the sensing unit be made up of diffraction grating, analysis grating and PN junction array, thus extend the function application of optical sensor system, and technological design is simple, is suitable for extensive industrialization and makes.

In the above-described embodiments, only to invention has been exemplary description, but those skilled in the art can carry out various amendment to the present invention without departing from the spirit and scope of the present invention after reading present patent application.

Claims (5)

1. the optical sensor system based on CMOS processing technology, comprise the integrated computing circuit being arranged on the optical sensor on cmos circuit plate and being connected with optical sensor, it is characterized in that: described optical sensor is formed by sensing unit array, described sensing unit comprises diffraction grating, analyze grating and PN junction array, described diffraction grating and analysis grating are the metal wiring layer of dual-layer Parallel vibrational power flow at described circuit board, described analysis parallel gratings is arranged on the below of described diffraction grating, the vertical range analyzed between grating and diffraction grating is that the m/n of distance protects doubly in diffraction grating Thailand, m and n is positive integer, described analysis grating forms dislocation to described diffraction grating at a certain distance and blocks, described PN junction array is positioned at the below of described analysis grating and is arranged at the layer-of-substrate silicon of described cmos circuit plate,

Corresponding to each PN junction, one is blocked the width of grating or the width increase D/N in grating space at described analysis grating intermediate reach, D is the pitch of described diffraction grating, N be more than or equal to 2 integer, form described analysis grating and at a certain distance dislocation formed to described diffraction grating and block.

2. a kind of optical sensor system based on CMOS processing technology according to claim 1, is characterized in that: the diffraction grating of described sensing unit is mutually vertical between two forms sensing unit pair.

3. a kind of optical sensor system based on CMOS processing technology according to claim 1, is characterized in that: the vertical range between described analysis grating and described diffraction grating is that distance is protected by 1/2 times of diffraction grating Thailand.

4. a kind of optical sensor system based on CMOS processing technology according to claim 1, is characterized in that: described N is more than or equal to 4.

5. a kind of optical sensor system based on CMOS processing technology according to the arbitrary claim of Claims 1-4, is characterized in that: described computing circuit be made up of CMOS adder, subtracter, divider and arctangent cp cp operation circuit the anti-computing circuit releasing plane angular information is calculated to the signal that described PN junction array exports.