阅读说明：本技术 一种近红外响应增强型硅雪崩探测器模块及其制造方法 (Near-infrared response enhanced silicon avalanche detector module and manufacturing method thereof ) 是由 张兴 高传顺 景媛媛 黄建 冉建 黄烈云 黄绍春 向勇军 于 2021-07-23 设计创作，主要内容包括：本发明属于光电探测领域,具体涉及一种近红外响应增强型硅雪崩探测器模块及其制造方法,该模块包括硅雪崩探测器芯片和前置放大电路,硅雪崩探测器芯片与前置放大电路连接；所述硅雪崩探测器芯片自上向下依次包括正面钝化层、N电极、N～(+)有源区、P～(-)雪崩区、P型衬底层、P～(+)光敏区、背面钝化层、增透层以及P电极,在P～(+)光敏区内设置有P～(+)截止环和N～(+)保护环；所述硅雪崩探测器芯片用于将脉冲光信号转换为脉冲电流信号,所述前置放大电路用于将脉冲电流信号进行放大输出；本发明创造性地提出了在探测器芯片背面集成微结构以提高近红外响应度,优化高能注入工艺以降低芯片的偏压温度系数,同时突破性地提出了双保护环结构以提高芯片的可靠性。(The invention belongs to the field of photoelectric detection, and particularly relates to a near-infrared response enhanced silicon avalanche detector module and a manufacturing method thereof, wherein the module comprises a silicon avalanche detector chip and a preamplification circuit, and the silicon avalanche detector chip is connected with the preamplification circuit; the silicon avalanche detector chip sequentially comprises a front passivation layer, an N electrode and N from top to bottom + Active region, P ‑ Avalanche region, P-type substrate layer, P + A photosensitive region, a back passivation layer, an anti-reflection layer and a P electrode in the P region + Is provided with P in the photosensitive region + A cut-off ring and N + A guard ring; the silicon avalanche detector chip is used for converting pulse optical signals into pulse current signalsThe pre-amplification circuit is used for amplifying and outputting the pulse current signal; the invention creatively provides a method for integrating a microstructure on the back of a detector chip to improve the near infrared responsivity, optimizes a high-energy injection process to reduce the bias temperature coefficient of the chip, and breakthroughs a double-protection-ring structure to improve the reliability of the chip.)

1. A near-infrared response enhanced silicon avalanche detector module comprises a silicon avalanche detector chip and a pre-amplification circuit, wherein the silicon avalanche detector chip is connected with the pre-amplification circuit to form electrical conduction; the silicon avalanche detector chip is characterized by comprising a front passivation layer (1), an N electrode (2) and N in sequence from top to bottom⁺Active region (3), P^-Avalanche region (4), P-type substrate layer (5), P⁺A photosensitive region (6), a back passivation layer (7), an anti-reflection layer (8) and a P electrode (9) at P⁺P is arranged in the photosensitive area (6)⁺A stop ring (10) and N⁺A guard ring (11); the silicon avalanche detector chip is used for converting pulse optical signals into pulse current signals, and the pre-amplification circuit is used for amplifying and outputting the pulse current signals.

2. The near-infrared response enhanced silicon avalanche detector module of claim 1 wherein P is⁺A stop ring (10) and N⁺The position of the protective ring (11) is P⁺A stop ring (10) is arranged on the front surface P^-Around the avalanche region (4), N⁺A guard ring (11) is arranged at N⁺Around the active region (3), and two N⁺The guard rings (11) are arranged on the inner side of the silicon avalanche detector chip, and two P-shaped guard rings⁺The stop ring (10) is arranged outside the silicon avalanche detector chip.

3. The near-infrared response enhanced silicon avalanche detector module according to claim 1, wherein the response wavelength range of the silicon avalanche detector chip is not 400nm to 1100 nm.

4. The near-infrared response enhanced silicon avalanche detector module according to claim 1, wherein the shape of the photosensitive surface of the silicon avalanche detector chip is not limited to a circle, and can be a regular shape or an irregular shape.

5. The near-infrared response enhanced silicon avalanche detector module according to claim 1, wherein the photo-sensitive surface pixels of the silicon avalanche detector chip are not limited to single quadrant, and can be two-quadrant, four-quadrant, eight-quadrant and array structure.

6. The near-infrared response enhanced silicon avalanche detector module according to claim 1, wherein the pre-amplification circuit comprises a cross-group impedance amplification structure, a resistance sampling amplification structure and an integral amplification structure; the output end of the cross-group anti-amplification structure is connected with the input end of the resistance sampling amplification structure, and the output end of the resistance sampling amplification structure is connected with the input end of the integral amplification junction structure, so that a pre-amplification circuit is formed.

7. The near-infrared response enhanced silicon avalanche detector module according to claim 6, wherein the cross-group anti-amplification structure in the preamplifier includes: a first operational amplifier, a feedback resistor R_fMatching capacitor C₁Matching resistor R₁(ii) a The matching capacitor C₁And a matching resistance R₁After being connected in parallel, the output end of the parallel-connection operational amplifier is connected with the anode of the first operational amplifier, and the input end of the parallel-connection operational amplifier is grounded; feedback resistor R_fThe input end of the first operational amplifier is connected with the negative electrode of the first operational amplifier, and the output end of the first operational amplifier is connected with the output end of the first operational amplifier, so that a cross-group impedance amplification structure is formed.

8. The module of claim 6, wherein the front-end is configured as a near-infrared response enhanced silicon avalanche detectorThe resistance sampling amplifying structure in the amplifier comprises a second operational amplifier, a first matching resistor R₂A second matching resistor R₃And a feedback resistor R_f1(ii) a The first matching resistor R₂One end of the first operational amplifier is connected with the grounding wire, and the other end of the first operational amplifier is connected with the anode of the second operational amplifier; the second matching resistor R₃One end of the first operational amplifier is connected with the grounding wire, and the other end of the first operational amplifier is connected with the negative electrode of the second operational amplifier; the feedback resistor R_f1One end of the second operational amplifier is connected with the negative electrode of the second operational amplifier, and the other end of the second operational amplifier is connected with the output end of the second operational amplifier to form a resistance sampling amplification structure.

9. The near-infrared response enhanced silicon avalanche detector module according to claim 6, wherein the integrating amplification structure in the preamplifier includes: third operational amplifier and feedback capacitor C_f(ii) a The anode of the third operational amplifier is grounded, and the feedback capacitor C_fOne end of the second operational amplifier is connected with the negative electrode of the third operational amplifier, and the other end of the second operational amplifier is connected with the output end of the third operational amplifier, so that an integral amplification structure is obtained.

10. A method of fabricating a near-infrared response enhanced silicon avalanche detector module, comprising:

s1: thermal oxidation growth of SiO on the surface of the P-type high-resistance monocrystalline silicon substrate₂A passivation film forming a front passivation layer (1);

s2: p is sequentially manufactured by utilizing photoetching process and ion implantation process⁺A stop ring (10), N⁺Guard ring (11), P^-Avalanche region (4), N⁺An active region (3);

s3: thinning and polishing the back of the P-type high-resistance monocrystalline silicon substrate;

s4: growing SiO on the back of the P-type high-resistance monocrystalline silicon substrate by thermal oxidation₂A passivation film forming a back passivation layer (7);

s5: p is manufactured on the back of the P-type high-resistance monocrystalline silicon substrate by utilizing a double-sided photoetching process and an ion implantation process⁺A photosensitive region (6);

s6: depositing a silicon nitride antireflection film (8) on the back surface by using an LPCVD (low pressure chemical vapor deposition) process;

s7: respectively manufacturing a P electrode hole and an N electrode hole by utilizing a double-sided photoetching process and a dry etching process;

s8: manufacturing an N electrode (2) and a P electrode (9) by utilizing a double-sided photoetching process or a metal sputtering process;

s9: welding the thick film circuit on the tube seat by adopting a reflow soldering process;

s10: the manufacturing of the pre-amplification circuit is completed by adopting a sintering pressure welding process;

s11: and sealing and welding the pipe cap and the pipe seat together by adopting an energy storage welding process to form the module.

Technical Field

The invention belongs to the field of photoelectric detection, and particularly relates to a near-infrared response enhanced silicon avalanche detector module and a manufacturing method thereof.

Background

The silicon avalanche photodetector module mainly comprises a silicon avalanche detector chip and a preamplification circuit, and the working principle is as follows: the silicon avalanche detector chip converts pulse optical signals into pulse current signals, converts the pulse optical signals into voltage signals through the preamplification circuit and amplifies and outputs the voltage signals, meets the processing requirement of a follow-up circuit, and is widely applied to the fields of military or civil laser ranging, laser countermeasure systems, laser radars and the like. The silicon avalanche photodetector module is used as a core sensing device for laser ranging, the ranging capability of the ranging system is closely related to the responsivity of the silicon avalanche photodetector module, and the module responsivity is determined by the photoelectric conversion capability of an avalanche detector chip, so that how to improve the responsivity of the silicon material in a near infrared response waveband plays a key role in the ranging capability of the laser ranging system.

The silicon material response wave band is 400-1100 nm, a typical near infrared response wave band 1064nm applied by a user is close to the cut-off wavelength on the silicon material response wave band, the absorption efficiency of the silicon material in the wave band is low, and the photoelectric conversion responsivity is less than 0.1A/W (the responsivity is 10A/W due to the self-carrying gain of the avalanche detector). The responsivity of the corresponding device in foreign countries is 0.36A/W, and the difference is large.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a near-infrared response enhanced silicon avalanche detector module, which comprises a silicon avalanche detector chip and a preamplification circuit, wherein the silicon avalanche detector chip is connected with the preamplification circuit to form electrical conduction; the silicon avalanche detector chip sequentially comprises a front passivation layer 1, an N electrode 2 and N from top to bottom⁺An active region 3, a P-avalanche region 4, a P-type substrate layer 5, P⁺A photosensitive region 6, a back passivation layer 7, an anti-reflection layer 8 and a P electrode 9 at P⁺P is arranged in the photosensitive region 6⁺Stop rings 10 and N⁺A guard ring 11; the silicon avalanche detector chip is used for converting pulse optical signals into pulse current signals, and the pre-amplification circuit is used for amplifying and outputting the pulse current signals.

Preferably, P is⁺Stop rings 10 and N⁺Guard ring 11 is provided at a position P⁺A stop ring 10 is arranged around the front P-avalanche region 4, N⁺Guard ring 11 is provided at N⁺Around the active region 3, and two N⁺The guard ring 11 is arranged at the inner side of the silicon avalanche detector chip, and two P⁺The stop ring 10 is arranged outside the silicon avalanche detector chip.

Preferably, the response wavelength range of the silicon avalanche detector chip is not 400nm to 1100 nm.

Preferably, the shape of the photosensitive surface of the silicon avalanche detector chip is not limited to a circular shape, and can be a regular shape structure or an irregular shape structure.

Preferably, the photosensitive surface pixel of the silicon avalanche detector chip is not limited to a single quadrant, and can be in a two-quadrant, four-quadrant, eight-quadrant and array structure.

Preferably, the pre-amplification circuit comprises a cross-group anti-amplification structure, a resistance sampling amplification structure and an integral amplification structure; the output end of the cross-group anti-amplification structure is connected with the input end of the resistance sampling amplification structure, and the output end of the resistance sampling amplification structure is connected with the input end of the integral amplification junction structure, so that a pre-amplification circuit is formed.

Further, the cross-group impedance amplifying structure in the preamplifier comprises: a first operational amplifier, a feedback resistor R_fMatching capacitor C₁Matching resistor R₁(ii) a The matching capacitor C₁And a matching resistance R₁After being connected in parallel, the output end of the parallel-connection operational amplifier is connected with the anode of the first operational amplifier, and the input end of the parallel-connection operational amplifier is grounded; feedback resistor R_fThe input end of the first operational amplifier is connected with the negative electrode of the first operational amplifier, and the output end of the first operational amplifier is connected with the output end of the first operational amplifier, so that a cross-group impedance amplification structure is formed.

Further, the resistance sampling amplifying structure in the preamplifier comprises: a second operational amplifier, a first matching resistor R₂A second matching resistor R₃And a feedback resistor R_f1(ii) a The first matching resistor R₂One end of the first operational amplifier is connected with the grounding wire, and the other end of the first operational amplifier is connected with the anode of the second operational amplifier; the second matching resistor R₃One end of the first operational amplifier is connected with the grounding wire, and the other end of the first operational amplifier is connected with the negative electrode of the second operational amplifier; the feedback resistor R_f1One end of the second operational amplifier is connected with the negative electrode of the second operational amplifier, and the other end of the second operational amplifier is connected with the output end of the second operational amplifier to form a resistance sampling amplification structure.

Further, the integral amplifying structure in the preamplifier includes: third operational amplifier and feedback capacitor C_f(ii) a The anode of the third operational amplifier is grounded, and the feedback capacitor C_fOne end of the second operational amplifier is connected with the negative electrode of the third operational amplifier, and the other end of the second operational amplifier is connected with the output end of the third operational amplifier, so that an integral amplification structure is obtained.

A method of manufacturing a near-infrared response enhanced silicon avalanche detector module, the method comprising:

s1: thermal oxidation growth of SiO on the surface of the P-type high-resistance monocrystalline silicon substrate₂A passivation film forming a front passivation layer;

s2: p is sequentially manufactured by utilizing photoetching process and ion implantation process⁺Stop ring 10, N⁺Guard ring 11, P-avalanche region 4, N⁺An active region 3;

s3: thinning and polishing the back of the P-type high-resistance monocrystalline silicon substrate;

s4: growing SiO on the back of the P-type high-resistance monocrystalline silicon substrate by thermal oxidation₂A passivation film forming a back passivation layer;

s5: p is manufactured on the back of the P-type high-resistance monocrystalline silicon substrate by utilizing a double-sided photoetching process and an ion implantation process⁺A photosensitive region 6;

s6: depositing a silicon nitride antireflection film 8 on the back by using an LPCVD (low pressure chemical vapor deposition) process;

s7: respectively manufacturing a P electrode hole and an N electrode hole by utilizing a double-sided photoetching process and a dry etching process;

s8: manufacturing an N electrode 2 and a P electrode 9 by using a double-sided photoetching process or a metal sputtering process;

s9: welding the thick film circuit on the tube seat by adopting a reflow soldering process;

s10: the manufacturing of the pre-amplification circuit is completed by adopting a sintering pressure welding process;

s11: and sealing and welding the pipe cap and the pipe seat together by adopting an energy storage welding process to form the module.

The invention creatively provides a method for integrating a microstructure on the back of a detector chip to improve the near infrared responsivity, optimizes a high-energy injection process to reduce the bias temperature coefficient of the chip, and breakthroughs a double-protection-ring structure to improve the reliability of the chip; the near-infrared response enhanced silicon avalanche detector module provided by the invention enables the responsivity of the device to be improved from less than 0.1A/W to 0.3A/W.

Drawings

FIG. 1 is an overall structural diagram of a silicon avalanche detector chip of the present invention;

FIG. 2 is a schematic circuit diagram of a near-infrared response enhanced silicon avalanche detector module according to the present invention;

FIG. 3 is a schematic diagram of a transimpedance amplifying structure according to the present invention;

FIG. 4 is a schematic diagram of a resistor sampling amplifying structure according to the present invention;

FIG. 5 is a schematic diagram of an integral amplifying structure according to the present invention;

FIG. 6 is a process flow diagram of a back side response enhancement microstructure of the present invention;

FIG. 7 is a flow chart of the ion implantation dose control method of the silicon avalanche detector chip according to the present invention;

FIG. 8 is a schematic diagram of ion implantation dose correction for a silicon avalanche detector chip according to the present invention;

FIG. 9 is a pictorial view of a silicon avalanche detector chip of the present invention;

FIG. 10 is a waveform diagram of a conventional distance measurement implementation;

wherein, 1, a front passivation layer, 2, an N electrode, 3, N⁺Active region, 4, P-avalanche region, 5, P-type substrate layer, 6, P⁺Photosensitive area, 7, back passivation layer, 8, antireflection layer, 9, P electrode, 10 and P⁺Stop ring, 11, N⁺A guard ring.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, and the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.

A near-infrared response enhanced silicon avalanche detector module comprises a silicon avalanche detector chip and a pre-amplification circuit, wherein the silicon avalanche detector chip is used for converting pulse optical signals into pulse current signals, the pre-amplification circuit is used for amplifying and outputting the pulse current signals, and the silicon avalanche detector chip is electrically conducted with the pre-amplification circuit. The silicon avalanche photodetector module has the characteristics of high response speed, high sensitivity, small size and the like, and can be widely applied to the fields of military or civil laser ranging, laser countermeasure systems, laser radars and the like.

As shown in fig. 1, a specific embodiment of a silicon avalanche detector chip includes: the silicon avalanche detector comprises a silicon avalanche detector chip and a pre-amplification circuit, wherein the silicon avalanche detector chip is electrically conducted with the pre-amplification circuit; the silicon avalanche detector chip sequentially comprises a front passivation layer 1, an N electrode 2 and N from top to bottom⁺An active region 3, a P-avalanche region 4, a P-type substrate layer 5, P⁺A photosensitive region 6, a back passivation layer 7, an anti-reflection layer 8 and a P electrode 9 at P⁺In the photosensitive region 6 is provided withP⁺Stop rings 10 and N⁺A guard ring 11; the silicon avalanche detector chip is used for converting pulse optical signals into pulse current signals, and the pre-amplification circuit is used for amplifying and outputting the pulse current signals.

P⁺Stop rings 10 and N⁺Guard ring 11 is provided at a position P⁺A stop ring 10 is arranged around the front P-avalanche region 4, N⁺Guard ring 11 is provided at N⁺Around the active region 3, and two N⁺The guard ring 11 is arranged at the inner side of the silicon avalanche detector chip, and two P⁺The stop ring 10 is arranged outside the silicon avalanche detector chip.

Optionally, the response wavelength of the silicon avalanche photodetector chip covers 400nm to 1100 nm.

Optionally, the shape of the photosensitive surface of the silicon avalanche photodetector chip is not limited to a circle, and includes all shapes such as a long strip, a square, an irregular shape, and a polygon.

Optionally, the photosensitive surface of the silicon avalanche photodetector chip is not limited to a single quadrant, but also includes multi-pixel structures such as a two-quadrant, a four-quadrant, an eight-quadrant, an array, and the like.

Optionally, the silicon avalanche photodetector chip structure includes a front-illuminated and a back-illuminated structure.

An embodiment of a circuit structure of a near-infrared response enhanced silicon avalanche detector module comprises: 3 resistors, 3 capacitors, 1 diode, 1 feedback resistor, 1 triode, an operational amplifier and 1 Avalanche Photodiode (APD); the specific connection relationship of the respective circuit elements is shown in fig. 2.

A circuit structure of a near-infrared response enhanced silicon avalanche detector module comprises a cross-group anti-amplification structure, a resistance sampling amplification structure and an integral amplification structure; the output end of the cross-group anti-amplification structure is connected with the input end of the resistance sampling amplification structure, and the output end of the resistance sampling amplification structure is connected with the input end of the integral amplification junction structure, so that a pre-amplification circuit is formed.

As shown in fig. 3, the first operational amplifier of the trans-group impedance amplifying structure and the feedback resistor R_fMatching capacitor C₁Pieces ofMatching resistor R₁(ii) a The matching capacitor C₁And a matching resistance R₁After being connected in parallel, the output end of the parallel-connection operational amplifier is connected with the anode of the first operational amplifier, and the input end of the parallel-connection operational amplifier is grounded; feedback resistor R_fThe input end of the first operational amplifier is connected with the negative electrode of the first operational amplifier, and the output end of the first operational amplifier is connected with the output end of the first operational amplifier, so that a cross-group impedance amplification structure is formed. The calculation expression of the cross-group impedance amplification structure is as follows:

U_o＝I_p*R_f

wherein, U_oRepresenting the output voltage, Ip the input current, R_fRepresenting the feedback resistance.

As shown in fig. 4, the resistance sampling amplifying structure in the preamplifier includes: a second operational amplifier, a first matching resistor R₂A second matching resistor R₃And a feedback resistor R_f1(ii) a The first matching resistor R₂One end of the first operational amplifier is connected with the grounding wire, and the other end of the first operational amplifier is connected with the anode of the second operational amplifier; the second matching resistor R₃One end of the first operational amplifier is connected with the grounding wire, and the other end of the first operational amplifier is connected with the negative electrode of the second operational amplifier; the feedback resistor R_f1One end of the second operational amplifier is connected with the negative electrode of the second operational amplifier, and the other end of the second operational amplifier is connected with the output end of the second operational amplifier to form a resistance sampling amplification structure. The calculation expression of the resistance sampling amplification structure is as follows:

U_o＝I_p*R₂*Av

Av＝R_f1/R₃

wherein, I_pRepresenting the input current, R₂Denotes the first matching resistance, Av denotes the amplification factor, R_f1Representing the feedback resistance, R₃Representing a second matching resistance.

As shown in fig. 5, the integral amplifying structure in the preamplifier includes: third operational amplifier and feedback capacitor C_f(ii) a The anode of the third operational amplifier is grounded, and the feedback capacitor C_fOne end of the second operational amplifier is connected with the negative electrode of the third operational amplifier, and the other end of the second operational amplifier is connected with the output end of the third operational amplifier, so that an integral amplification structure is obtained. The calculation expression of the integral amplification structure is as follows:

U_o＝1/C_f∫I_pdt

wherein, U_oRepresenting the output voltage, Ip the input current, C_fDenotes a feedback capacitance, t denotes time, and ^ denotes an integral operation.

One embodiment of a method for manufacturing a near-infrared response enhanced silicon avalanche detector module, as shown in fig. 6, comprises:

s1: thermal oxidation growth of SiO on the surface of the P-type high-resistance monocrystalline silicon substrate₂A passivation film forming a front passivation layer;

s2: p is sequentially manufactured by utilizing photoetching process and ion implantation process⁺Stop ring 10, N⁺Guard ring 11, P-avalanche region 4, N⁺An active region 3;

s3: thinning and polishing the back of the P-type high-resistance monocrystalline silicon substrate;

s4: growing SiO on the back of the P-type high-resistance monocrystalline silicon substrate by thermal oxidation₂A passivation film forming a back passivation layer;

s5: p is manufactured on the back of the P-type high-resistance monocrystalline silicon substrate by utilizing a double-sided photoetching process and an ion implantation process⁺A photosensitive region 6;

s6: depositing a silicon nitride antireflection film 8 on the back by using an LPCVD (low pressure chemical vapor deposition) process;

s7: respectively manufacturing a P electrode hole and an N electrode hole by utilizing a double-sided photoetching process and a dry etching process;

s8: manufacturing an N electrode 2 and a P electrode 9 by using a double-sided photoetching process or a metal sputtering process;

s9: welding the thick film circuit on the tube seat by adopting a reflow soldering process;

s10: the manufacturing of the pre-amplification circuit is completed by adopting a sintering pressure welding process;

s11: and sealing and welding the pipe cap and the pipe seat together by adopting an energy storage welding process to form the module.

The process of obtaining the silicon avalanche detector chip comprises the following steps: thinning and polishing the back of the silicon avalanche detector chip; carrying out photoetching microstructure pattern processing on the thinned and polished silicon avalanche detector chip; carrying out photoresist hot melting treatment on the silicon avalanche detector chip according to the photoetching microstructure diagram; transferring the pattern in the processed chip, and corroding the chip by a wet method to modify the appearance; and carrying out back ion implantation on the chip with the modified morphology, and carrying out back metallization after ion implantation to obtain the silicon avalanche detector chip.

As shown in fig. 7, the specific process of performing ion implantation on the silicon avalanche detector chip includes: carrying out ion implantation on the avalanche region; dividing the avalanche region into a formal wafer and a precedent wafer; firstly, carrying out ion implantation on a photosensitive area of the precedent piece in the precedent piece; after ion concentration is injected, a contact hole and an electrode are arranged on the precedent piece, and thinning and polishing treatment is carried out on the back surface of the precedent piece; performing breakdown voltage test on the thinned and polished preceding wafer, judging whether the breakdown voltage meets the test requirement, if not, adjusting ion implantation conditions, and performing ion implantation again on the photosensitive area of the preceding wafer; and if the requirements are met, performing ion implantation on the photosensitive area of the formal wafer according to the ion implantation conditions of the advanced wafer to obtain the silicon avalanche detector chip after ion implantation.

As shown in fig. 8, the impurity concentration of the ion implantation dose of the silicon avalanche detector chip is normally distributed with the distance from the position of the implanted ions to the chip surface. In the inverse type impurity distribution, the impurity concentration of the implanted ions first increases with the distance from the surface, and then decreases immediately after increasing to a certain extent. In the impurity distribution of the P region (avalanche region), the impurity concentration of the P region implanted ions increases with the distance from the implantation position, and decreases after increasing to a certain extent. The maximum impurity concentration of the P region is lower than that of the inversion impurity.

As shown in fig. 9, a near-infrared response enhanced silicon avalanche detector module includes an APD detector, a thick film circuit, a tube socket, and a tube cap; a silicon avalanche detector chip is arranged in the APD detector, and the APD detector is arranged in the thick film circuit; the thick film circuit is a pre-amplification circuit, is arranged on the tube seat and is connected with the output end of the thick film circuit through a guide pin to be led out; and carrying out airtight packaging on the near-infrared response enhanced silicon avalanche detector module by adopting a pipe cap.

Optionally, the thick film circuit is of a rectangular structure, a protruding structure is arranged in the center of the thick film circuit, and the APD detector is arranged on the protruding structure.

Optionally, the hermetic package includes a metal case hermetic package, and the package form includes a TO round package, a butterfly package, and the like.

In laser ranging applications, a laser ranging system mainly has two core indexes, namely, distance measurement and ranging precision measurement. The conventional distance measurement is realized as shown in the waveform of fig. 10, where the leading edge of the first pulse (main wave) is at time t_StartThe leading edge of the second pulse being at time t_StopDistance information is obtained through the difference of the two leading edge moments, and the formula for calculating the distance is as follows:

wherein, t_Stop2Indicating the time of the leading edge of the second pulse, t_Start1Indicating the time of the leading edge of the first pulse and C the speed of light.

In a laser ranging system, the conventional leading edge time obtaining mode is realized by AD sampling, the AD performs interval sampling on a pulse signal according to clock frequency, and the more jittered the leading edge of a pulse waveform (the smaller the rising time is), the more accurate the leading edge time of the AD sampling is, so the higher the ranging precision is; therefore, the key parameter of the detector module influencing the laser ranging system is the rise time, the avalanche detector module developed based on the method provided by the patent has the characteristic of high response speed, the response speed is positively correlated with the rise time, the rise time of the module is 2ns, and a solution is provided for high-precision ranging.

Furthermore, the distance measurement of the laser ranging system means whether the reflected laser intensity detector module can distinguish after the laser is emitted to reach the ranging target. Considering factors such as environment factor, distance measuring target characteristic and receiving antenna parameter, laser echo power P_rThe calculation formula of (2) is as follows:

wherein, P_iDenotes the total power of the laser pulse, beta denotes the attenuation coefficient of the atmosphere to the laser, L denotes the distance, theta_iRepresenting the emission angle of the laser beam, theta_rRepresenting the angle of reflection of the laser beam, T₁Representing the transmission of the transmitting antenna, T₂Denotes the transmissivity of the receiving antenna, gamma denotes the reflectivity of the target, S_eIndicating the reflection area of the ranging target, S_DThe receiving antenna area of the receiving antenna is indicated.

According to laser echo power P_rThe calculation formula of (2) shows that the echo power is inversely proportional to the distance, and the longer the distance is, the lower the echo power is. Therefore, the key detector module parameter affecting the measurement distance of the laser ranging system is sensitivity, and the higher the sensitivity, the longer the measurement distance. The avalanche detector module developed based on the method provided by the patent has the characteristic of high sensitivity, the sensitivity of the avalanche detector module is less than or equal to 10nW, the avalanche photodetector module is at the domestic advanced level and is equivalent to the parameters of an imported APD module, and a solution is provided for long-distance ranging.

Furthermore, in laser radar application, mainly including robot, AGV dolly, autopilot laser radar and unmanned aerial vehicle etc. of sweeping the floor. Robot and AGV dolly of sweeping the floor adopt single-point APD module, also are applicable to this patent. Automatic drive laser radar, unmanned aerial vehicle adopt a plurality of avalanche detector modules to form the array, receive echo signal through a plurality of detector modules and obtain target topography feature, can develop array detector chip and read-out circuit according to the proposal of this patent and realize, can also use to develop the module based on this patent and splice and realize for the array, consequently this patent proposes that the method also is applicable.

Further, in laser fuze and laser guidance applications, conventional PIN detector modules are currently in service. However, as the technology advances, the system has higher requirements on the action distance, and the proposal provided by the patent provides a solution for the new generation of laser fuze and laser guidance. Because the avalanche detector chip developed based on the avalanche photodetector chip has 100 times of internal avalanche gain, and is two orders of magnitude higher than the sensitivity of the traditional PIN detection module, the working distance can also be improved by two orders of magnitude.

The above-mentioned embodiments, which further illustrate the objects, technical solutions and advantages of the present invention, should be understood that the above-mentioned embodiments are only preferred embodiments of the present invention, and should not be construed as limiting the present invention, and any modifications, equivalents, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.