Based on standard integrated circuit technology low noise single photon detection chip and system
(1) technical field
The present invention relates to one kind to be based on standard integrated circuit technology low noise single photon detection chip and system, can use
In laser radar, DNA sequencing, the detection of the poles dim light such as the distribution of quantum secret key and medical imaging belongs to detecting technique neck
Domain.
(2) background technique
Single-photon detecting survey technology is a kind of detecting technique, and principle is using photoelectric effect, to incident single photon
It is counted, to realize the detection to atomic weak signal.It is atomic dim light measurement such as laser ranging, DNA sequencing, and quantum is close
Spoon distribution, the core of laser radar and medical imaging.As the progress and IC design of semiconductor process technique are horizontal
Raising, using standard integrated circuit technology design single-photon avalanche diode (Single Photon Avalanche
Diode) and by single-photon avalanche diode and relevant integrated circuit such as avalanche events sensor circuit, quenching circuit, and
Back end signal processing circuit etc. is integrated to be possibly realized on the same chip.Compared to traditional single-photon detectors such as photomultiplier transit
Manage (Photomultiplier Tube, PMT) or microchannel plate (Microchannel plate, MCP), such product
It running under lower bias voltage, there is smaller volume, lower power consumption is insensitive for electromagnetic noise, integrated level height,
It is low in cost, it is reproducible, it has broad application prospects.
In photon detection/imaging system based on single-photon avalanche diode, system passes through to two pole of single-photon avalanche
The avalanche events that the hole-electron pair generated inside pipe is excited are detected and are counted.Snowslide in single-photon avalanche diode
Breakdown events can not only be excited by photonic absorption, it is also possible to be excited by other factors.The snowslide being excited under no light condition
Event is unrelated with photonic absorption, is referred to as dark counting to the counting of these avalanche events.Dark count rate is two pole of single-photon avalanche
One important parameter of pipe, high dark count rate can reduce the signal-to-noise ratio of monochromatic light subsystem, increase error rate of system, increase imaging
(exposure) time of integral needed for system and reduction detectivity.Therefore, the dark count rate in single-photon avalanche diode
It needs to be reduced as far as possible.
In the integrated circuit technology of standard, for the injection depth of each layer, dopant concentration has solid chip foundries
Calibration is quasi-, also has certain limitation (such as density metal) for design rule, this causes in standard integrated circuit technology
The depletion layer for the single-photon avalanche diode prepared is narrow, is easy to be influenced by thermal excitation and tunnel-effect carrier,
There is higher dark count rate.In addition to this, due to lacking high annealing and going defect processing step, in two pole of single-photon avalanche
Higher impurity concentration can be generated around the photosensitive region of pipe, generate higher dark counting therewith.
In order to reduce the noise of single-photon detection system, researcher devises in different standard integrated circuit technologies
The single-photon avalanche diode chip of different structure promotes chip to the signal-to-noise ratio of single photon detection to reduce dark count rate.Such as
The photosensitive area that R.K.Henderson etc. is prepared under the technique of 90nm is 3.1 μm2Single-photon avalanche diode output
Dark counting is 250Hz (R.K.Henderson, et al., " A 3 × 3,5 μm of pitch, 3-transistor single
photon avalanche diode array with integrated 11 V bias generation in 90nm
CMOS technology,”IEEE International Electron Devices Meeting(IEDM),
pp.14.2.1–14.2.4.Dec.2010.);E.A.G.Webster is by using the p- in 90nm CMOS technology
Epitaxial layers and deep n-well layers are formed to constitute single-photon avalanche diode using p-epitaxial layers
Protection ring is mixed using its low to alleviate tunnel-effect.Their design reduces the dark counting of device to a certain extent
Rate (E.A.G.Webster, et al., " A single-photon avalanche diode in 90-nm CMOS
Imaging technology with 44%photon detection efficiency at 690nm, " IEEE
Electron Device Letters.,33(5):694–696,May 2012.).Although by structure optimization, single photon detection
The dark count rate of device chip has obtained a degree of alleviation, however its universal dark count rate has still reached single single photon
The dozens to hundreds of Hz of avalanche diode, this makes when it is applied to single-photon avalanche diode array, and global noise is still
It is very considerable.In addition to this, once peaceful to disclose " the high time resolution low noise single-photon detecting of optical pulse synchronization equal to 2010
Survey device " (Chinese patent: 201010292821.9), Gauss electricity is converted optical signal into using optical time delay unit and photoelectric conversion module
Signal reduces the noise that avalanche diode is caused by capacity effect as portal vein pulsed light signal, improves signal-to-noise ratio;Zhao Yan
It is vertical be equal to disclose " a kind of gate difference single-photon detection system " within 2015 and (Chinese patent: 201510413840.5), pass through
Feedback control mechanism is gated, the spike noise and afterpulse effect of system is reduced, improves look-in frequency;Huang Zinan is equal to
Disclose within 2016 the high-speed low-noise single-photon detector of gate " ultrashort pulse " (Chinese patent:
201710165360.0), use the adjustable ultrashort pulse signal of adjustable pulse width amplitude as gate-control signal, expanded using balance
The working frequency of the single-photon detector of scheme, and reduce effective pulsewidth of gate signal, it can effectively reduce miscount, visited in high speed
It remains to ensure that the high of spike noise inhibits ratio in survey, improves detector performance.The defect of these designs has: system described in 1.
It is only used for the single-photon avalanche diode worked under gating patterns, and the single-photon detector run under gating patterns is being believed
The unknown application of number photon arrival time, if luminous intensity detects, distance measurement, in laser radar and fiber optical time domain reflection instrument,
The loss for be easy to causeing useful photon to count, causes system detecting error;2. system described in is only applicable to single single photon
Avalanche diode is needed if required to single-photon avalanche diode array for each of array single-photon avalanche diode
Related system is designed, considerably increases single-photon avalanche diode array system volume and complexity, while reducing detection
The detection efficient of device system;3. the matched capacitance module of used and single-photon avalanche diode progress (or PIN photoelectricity is visited
Survey device) with single-photon avalanche diode not on the same chip, when having incident light beam strikes to single-photon avalanche diode and trigger
When avalanche effect, the temperature of single-photon avalanche diode can change, and internal equivalent parameters (capacitor, resistance etc.) can also become
Change, will cause single-photon avalanche diode in this way can not match with equivalent modules used (capacitor or PIN photoelectric detector),
Cause systematic error.
In order to solve problem above, the invention discloses one kind to be based on standard integrated circuit technology low noise single photon detection
Chip and system can be used for laser radar, DNA sequencing, the detection of the poles dim light such as the distribution of quantum secret key and medical imaging.This hair
It is bright in single photon detection chip by one or more single-photon avalanche diode in single-photon avalanche diode array
Photosensitive part is covered with metal layer, runs it under dark situation, only provides dark counting.The single-photon avalanche run under dark situation
Diode is due to the single-photon avalanche diode phase that runs under structure, size and operating parameter and normal mode on same chip
Together, there can be identical dark count rate.This dark counting be used to reduce the noise of whole system, and (dark count rate theoretically can be with
It drops to close to 0), for improving the sensitivity and detection dynamic range of system.Single-photon avalanche diode number of arrays on chip
Amount is bigger, and the effect of noise reduction is more obvious.The single-photon avalanche diode that present invention can apply to work under any mode, including
Gating patterns are passively quenched and mode are actively quenched, greatly improve its application range.The system need to only avenge single photon
The a part collapsed in diode array is handled (one or more), single without carrying out to all single-photon avalanche diodes
Reason of staying alone and system design, reduce system bulk and complexity, while helping to promote photon detection efficiency, this makes institute
The system of stating is more suitable for single-photon detector array system.All single photons for being used to carry out single photon detection in the system
Avalanche diode is on same chip, is same structure, same size and is worked under same bias voltage, therefore
There are the operating temperature and performance of identical (or close), this makes its noise reduction effect will not be by single-photon detector chip temperature
Variation is influenced.In addition to this, the present invention can be completed under standard integrated circuit technology (such as by the sense of single-photon avalanche diode
Light part is covered with metal layer), while it being applicable to the single-photon detector array chip of different structure, this makes the present invention can
To be carried out simultaneously with other optimization means such as single-photon avalanche diode structure optimizations, further to promote single-photon detection system
Performance.
(3) summary of the invention
The purpose of the present invention is to provide a kind of low noise single-photon detection systems by light source 1, biasing module 2, single photon
Detection chip 3, signal processing system 4 form, two pole of single-photon avalanche that wherein single photon detection chip 3 is run by normal mode
Single-photon avalanche diode 32 and avalanche events detection circuit array 33 composition run under pipe 31, dark situation.
The object of the present invention is achieved like this:
Biasing module 2 generates controllable reverse bias voltage and exports to single photon detection chip 3, single photon detection chip
All single-photon avalanche diodes in 3 are offset under identical voltage, and the light that light source 1 issues is incident to single photon detection core
The output of single-photon avalanche diode 31 of piece 3, the normal mode operation in single photon detection chip 3 includes noise-excitation and photon
Avalanche events electric pulse including excitation, and regular transistor-transistor is converted to by avalanche events detection circuit array 33
Logic level (TTL) signal is exported to signal processing system 4, and dark situation snows the single photon of operation in single photon detection chip 3
It collapses the avalanche events electric pulse of 32 output noises of diode excitation and TTL is converted to by avalanche events detection circuit array 33
Signal is exported to signal processing system 4, and signal processing system 4 carries out photon meter to the TTL signal that single photon detection chip 3 exports
Digit rate calculates and noise reduction calculates and processing, finally provides detection result.
Light source 1 in the system can be the fluorescent exciting signal in fluorescence detection system, optical time domain reflection system
In Ruili reflected light signal, the signal of communication in communication system, interference signal and surface in fiber optic sensor system etc.
One kind of the various optical signals such as the reflection signal of ion resonance detection system.
Single photon detection chip 3 in the system is the chip based on standard integrated circuit technology, and manufacturing process can be with
It is standard CMOS technique (CMOS), bipolar CMOS technique (BiCMOS),
Times of silicon wafer insulator CMOS technology (SOI CMOS) and cmos image sensor technique (CIS)
Anticipate one kind, process can be 0.8 μm, 0.35 μm, 0.18 μm, 0.13 μm, it is any one in 90nm, 65nm and 45nm
Kind.The structure of single-photon avalanche diode in single photon detection chip 3 can by p+, the n+ in standard integrated circuit technology,
The difference such as nwell, pwell, Deep-nwell, P-epitaxial and P-subtrate mix layer certain several constituted
, shape can be circular, ellipse, square, one of shapes such as rectangle.
The optical detection part of single photon detection chip 3 is made of single-photon avalanche diode array, all lists in array
Photon avalanches diode is on same chip, have same structure, same size and in same bias voltage and
At a temperature of work.N number of single-photon avalanche diode (N >=1) is chosen in an array, with a gold in standard integrated circuit technology
Belong to layer to cover photosensitive region, run it under dark situation, forms the single-photon avalanche diode run under dark situation
32, the avalanche events electric pulse of output noise excitation and to be converted to TTL signal by avalanche events detection circuit array 33 defeated
Out to signal processing system 4;Remaining single-photon avalanche diode then works under normal mode, the operation of these normal modes
Single-photon avalanche diode 31 exports the avalanche events electric pulse including noise-excitation and photon excitation, and passes through snowslide
Event detection circuit array 33 is converted to TTL signal and exports to signal processing system 4.Snowslide thing in single photon detection chip 3
Part detection circuit array 33 can be amplitude discriminator circuit, current-to-voltage converting circuit, voltage comparator circuit and quenching circuit
It is any.
The signal processing system 4 can be based on microcontroller, field programmable gate array (FPGA) and
Any one of the signal processing system of computer.Signal processing system 4 receives snowslide event detection in single photon detection chip 3
The TTL signal that gate array 33 exports obtains the single-photon avalanche diode 31 of normal mode operation and dark by calculating respectively
The pulsimeter digit rate that the single-photon avalanche diode 32 run under environment is exported.The single photon snow of all normal mode operations
The average counter rate for collapsing diode 31 removes the average counter rate of the single-photon avalanche diode 32 run under all dark situations, then
Number multiplied by the single-photon avalanche diode 31 of normal mode operation is then output of the whole detection system after removing noise
Photon count rate.If the number for the single-photon avalanche diode 3 that normal mode is run in single photon detection chip 3 is M, Mei Gedan
It is respectively CR that photon avalanches diode, which exports pulsimeter digit rate to be,1、CR2、CR3...CRM, the single-photon avalanche that runs under dark situation
The number of diode 32 is N, and each step-by-step counting is CRD1、CRD2、 CRD3...CRDN, then whole single-photon detection system
The output photon counting rate (CR) after removing noise are as follows:
(4) Detailed description of the invention
Fig. 1 is based on the low noise single photon detection chip of standard integrated circuit technology and its structural schematic diagram of system.
Low noise single-photon detection system is made of light source 1, biasing module 2, single photon detection chip 3, signal processing system 4, wherein
The single-photon avalanche two run under single-photon avalanche diode 31 that single photon detection chip 3 is run by normal mode, dark situation
Pole pipe 32 and avalanche events detection circuit array 33 form.
Fig. 2 is showing for the embodiment one of low noise single photon detection chip and its system based on standard integrated circuit technology
It is intended to.Low noise single-photon detection system is made of light source 1, biasing module 2, single photon detection chip 3, signal processing system 4,
Single-photon avalanche diode 31 that wherein single photon detection chip 3 is run by normal mode, dark situation snow the single photon of operation
It collapses diode 32 and avalanche events detection circuit array 33 forms.In system the optical detection part of single photon detection chip 3 by
One 1 × 6 single-photon avalanche diode array is constituted, and it is integrated with standard to choose 1 single-photon avalanche diode in an array
A metal layer in circuit technology is covered, and runs it under dark situation, is formed dark situation and is snowed the single photon of operation
Diode 32 is collapsed, the avalanche events electric pulse of output noise excitation is simultaneously converted to by avalanche events detection circuit array 33
TTL signal is exported to signal processing system 4;Remaining single-photon avalanche diode then works under normal mode, these are normal
The single-photon avalanche diode 31 of mode operation exports the avalanche events electric pulse including noise-excitation and photon excitation, and
TTL signal is converted to by avalanche events detection circuit array 33 to export to signal processing system 4.
Fig. 3 is the single-photon avalanche diode run under the single-photon avalanche diode and dark situation that normal mode is run
Structural schematic diagram under standard integrated circuit technology.The PN junction (avalanche multiplication area) of single-photon avalanche diode is formed in p+ floor
Pwell is injected and between nwell layers, in structure around the region p+ to form a lower guarantor mixed around multiplication regions
Retaining ring is isolated high electric field.The photosensitive region of the single-photon avalanche diode 32 run under dark situation has one layer of metal
Layer covering (metal3) runs on it in dark situation, will not generate the avalanche events excited by absorption photon, only exports dark
It counts.By the statistics to dark counting, for reducing detection system noise.
Fig. 4 is showing for the embodiment one of low noise single photon detection chip and its system based on standard integrated circuit technology
It is intended to.Low noise single-photon detection system is made of light source 1, biasing module 2, single photon detection chip 3, signal processing system 4,
Single-photon avalanche diode 31 that wherein single photon detection chip 3 is run by normal mode, dark situation snow the single photon of operation
It collapses diode 32 and avalanche events detection circuit array 33 forms.In system the optical detection part of single photon detection chip 3 by
One 1 × 10 single-photon avalanche diode array is constituted, and 10 single-photon avalanche diodes in array are in same core
On piece is same structure, same size and same bias voltage and at a temperature of work.3 lists are chosen in an array
Photon avalanches diode is covered with a metal layer in standard integrated circuit technology, runs it under dark situation, shape
At the single-photon avalanche diode 32 run under dark situation, the avalanche events electric pulse of output noise excitation simultaneously passes through snowslide thing
Part detection circuit array 33 is converted to TTL signal and exports to signal processing system 4;Remaining single-photon avalanche diode then works
Under normal mode, the output of single-photon avalanche diode 31 of these normal modes operation includes noise-excitation and photon excitation
Avalanche events electric pulse inside, and TTL signal is converted to by avalanche events detection circuit array 33 and is exported to signal processing
System 4.
(5) specific embodiment
Below with reference to specific embodiment, the present invention is further explained.
Embodiment one:
Fig. 2 gives based on the low noise single photon detection chip of standard integrated circuit technology and its embodiment of system.
Low noise single-photon detection system is made of light source 1, biasing module 2, single photon detection chip 3, signal processing system 4, wherein
The single-photon avalanche two run under single-photon avalanche diode 31 that single photon detection chip 3 is run by normal mode, dark situation
Pole pipe 32 and avalanche events detection circuit array 33 form.Biasing module 2 generates controllable reverse bias voltage and exports extremely
Single photon detection chip 3, all single-photon avalanche diodes in single photon detection chip 3 are offset under identical voltage,
The light that light source 1 issues is incident to single photon detection chip 3, the single photon snow of the normal mode operation in single photon detection chip 3
Avalanche events electric pulse of the output of diode 31 including noise-excitation and photon excitation is collapsed, and passes through avalanche events and detects electricity
Road array 33 is converted to regular transistor-transistor logic level (TTL) signal and exports to signal processing system 4, single-photon detecting
It surveys the avalanche events electric pulse of 32 output noises of the single-photon avalanche diode excitation run under dark situation in chip 3 and passes through
Avalanche events detection circuit array 33 is converted to TTL signal and exports to signal processing system 4, and signal processing system 4 is to single photon
The calibration pulse that detection chip 3 exports carries out photon count rate and noise reduction calculates and processing, finally provides detection result.
The optical detection part of single photon detection chip 3 is made of one 1 × 6 single-photon avalanche diode array, array
In 6 single-photon avalanche diodes be on same chip, be same structure, same size and in same biased electrical
Pressure and at a temperature of work.A gold of 1 single-photon avalanche diode in standard integrated circuit technology is chosen in an array
Belong to layer to be covered, run it under dark situation, forms the single-photon avalanche diode 32 run under dark situation, only output is made an uproar
The avalanche events electric pulse of sound excitation is simultaneously converted to TTL signal and is exported to signal processing by avalanche events detection circuit array 33
System 4;Remaining single-photon avalanche diode then works under normal mode, the single-photon avalanche two of these normal modes operation
Pole pipe 31 exports the avalanche events electric pulse including noise-excitation and photon excitation, and passes through avalanche events detection circuit battle array
Column 33 are converted to TTL signal and export to signal processing system 4.
The single-photon avalanche diode 32 run under the single-photon avalanche diode 31 and dark situation of normal mode operation
Structure under standard integrated circuit technology is as shown in Figure 3.The PN knot (avalanche multiplication area) of single-photon avalanche diode is formed in
Pwell is injected between p+ layers and nwell layers, in structure around the region p+ to form a lower ginseng around multiplication regions
High electric field is isolated in miscellaneous protection ring.The photosensitive region of the single-photon avalanche diode 32 run under dark situation has one
Layer metal layer covering (Metal3) runs on it in dark situation, will not generate the avalanche events excited by absorption photon, only
Export dark counting.By the statistics to dark counting, for reducing detection system noise.
Signal processing system 4 receives the TTL letter that snowslide event detection circuit array 33 exports in single photon detection chip 3
Number, and by calculating the single photon run under the single-photon avalanche diode 31 and dark situation that obtain normal mode operation respectively
The pulsimeter digit rate that avalanche diode 32 is exported.The single-photon avalanche diode output of 5 normal mode operations in array
Pulsimeter digit rate is respectively CR1, CR2, CR3, CR4 and CR5, the single-photon avalanche diode output run under 1 dark situation
Pulsimeter digit rate is CRD1.Overall output photon count rate (CR after the noise reduction that signal processing system 4 obtainss) are as follows:
Embodiment two:
Fig. 4 gives based on the low noise single photon detection chip of standard integrated circuit technology and its embodiment of system.
Low noise single-photon detection system is made of light source 1, biasing module 2, single photon detection chip 3, signal processing system 4, wherein
The single-photon avalanche two run under single-photon avalanche diode 31 that single photon detection chip 3 is run by normal mode, dark situation
Pole pipe 32 and avalanche events detection circuit array 33 form.Biasing module 2 generates controllable reverse bias voltage and exports extremely
Single photon detection chip 3, all single-photon avalanche diodes in single photon detection chip 3 are offset under identical voltage,
The light that light source 1 issues is incident to single photon detection chip 3, the single photon snow of the normal mode operation in single photon detection chip 3
Avalanche events electric pulse of the output of diode 31 including noise-excitation and photon excitation is collapsed, and passes through avalanche events and detects electricity
Road array 33 is converted to regular transistor-transistor logic level (TTL) signal and exports to signal processing system 4, single-photon detecting
It surveys the avalanche events electric pulse of 32 output noises of the single-photon avalanche diode excitation run under dark situation in chip 3 and passes through
Avalanche events detection circuit array 33 is converted to TTL signal and exports to signal processing system 4, and signal processing system 4 is to single photon
The calibration pulse that detection chip 3 exports carries out photon count rate and noise reduction calculates and processing, finally provides detection result.
The optical detection part of single photon detection chip 3 is made of one 1 × 10 single-photon avalanche diode array, array
In 10 single-photon avalanche diodes be on same chip, be same structure, same size and similarly biasing
Voltage and at a temperature of work.3 single-photon avalanche diodes are chosen in an array with one in standard integrated circuit technology
Metal layer is covered, and runs it under dark situation, is formed the single-photon avalanche diode 32 run under dark situation, is only exported
The avalanche events electric pulse of noise-excitation is simultaneously converted to TTL signal and is exported to signal by avalanche events detection circuit array 33
Reason system 4;Remaining single-photon avalanche diode then works under normal mode, the single-photon avalanche of these normal modes operation
Diode 31 exports the avalanche events electric pulse including noise-excitation and photon excitation, and passes through avalanche events detection circuit
Array 33 is converted to TTL signal and exports to signal processing system 4.
Signal processing system 4 receives the TTL letter that snowslide event detection circuit array 33 exports in single photon detection chip 3
Number, and by calculating the single photon run under the single-photon avalanche diode 31 and dark situation that obtain normal mode operation respectively
The pulsimeter digit rate that avalanche diode 32 is exported.The single-photon avalanche diode output of 7 normal mode operations in array
Pulsimeter digit rate is respectively CR1, CR2, CR3, CR4, CR5, CR6 and CR7, two pole of single-photon avalanche run under 3 dark situations
The pulsimeter digit rate of pipe output is CRD1, CRD2And CRD3.Overall output after the noise reduction that signal processing system 4 obtains
Photon count rate (CRs) are as follows:
。