WO2013091280A1 - 中子敏感镀膜及其形成方法 - Google Patents

中子敏感镀膜及其形成方法 Download PDF

Info

Publication number
WO2013091280A1
WO2013091280A1 PCT/CN2012/001608 CN2012001608W WO2013091280A1 WO 2013091280 A1 WO2013091280 A1 WO 2013091280A1 CN 2012001608 W CN2012001608 W CN 2012001608W WO 2013091280 A1 WO2013091280 A1 WO 2013091280A1
Authority
WO
WIPO (PCT)
Prior art keywords
sensitive
reaction chamber
neutron
precursor
film
Prior art date
Application number
PCT/CN2012/001608
Other languages
English (en)
French (fr)
Inventor
杨祎罡
李元景
张勤俭
陆年华
宫辉
曾鸣
Original Assignee
同方威视技术股份有限公司
清华大学
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 同方威视技术股份有限公司, 清华大学 filed Critical 同方威视技术股份有限公司
Publication of WO2013091280A1 publication Critical patent/WO2013091280A1/zh

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
    • C23C16/455—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating characterised by the method used for introducing gases into reaction chamber or for modifying gas flows in reaction chamber
    • C23C16/45523—Pulsed gas flow or change of composition over time
    • C23C16/45525—Atomic layer deposition [ALD]
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
    • C23C16/455—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating characterised by the method used for introducing gases into reaction chamber or for modifying gas flows in reaction chamber
    • C23C16/45523—Pulsed gas flow or change of composition over time
    • C23C16/45525—Atomic layer deposition [ALD]
    • C23C16/45555—Atomic layer deposition [ALD] applied in non-semiconductor technology

Definitions

  • the present invention relates generally to neutron detection techniques in nuclear technology applications, and in particular to neutron sensitive coatings and methods of forming same. Background technique
  • nuclide that can be used to detect neutrons are very limited, typical nuclide has 3 He, 6 Li, 1 ( 1H and 155 ' 157 Gd, etc.. Among them, 3 He has already faced insufficient supply; 6 Li exists. The sensitivity is low and the formation of the detection medium is unstable; 155 ' 157 Gd has high sensitivity, but it produces charged particles with lower energy and more ⁇ , which is not conducive to the formation of neutron signals and high ⁇ / ⁇ suppression.
  • 1Q B as the probe nuclide is currently the best choice, so the following will focus on 1 Q B as an example.
  • 1D B as a neutron sensitive nuclides also exists for 6 Li and 155 ' 157 Gd, and the technical solution of the present invention is also applicable to 6 Li and 155 ' 157 Gd as neutron sensitive nuclides. In the application.
  • 1 Q B Since 1 Q B has a high thermal neutron absorption cross section of 3836b@25.3meV, it absorbs neutrons and emits charged particles with a probability of 100%, and the charged particles have higher energy (2.3 1 MeV), resulting in ⁇ -ray energy. Lower (478 keV), which makes it possible for 1 () B to achieve higher detection efficiency and better ⁇ / ⁇ rejection ratio.
  • the process of neutron measurement three steps are usually required: 1) detecting the medium to absorb neutrons; 2) neutrons are absorbed by the 1Q B nuclide in the detected medium, and the charged particles are emitted, and the charged particles are emitted from the detection medium; 3) The charged particles ejected from the detection medium are ionized in a gas (or solid surface) to form electrons and ions that are collected by the cathode and anode of the detector to form a signal.
  • the three parameters P, P 2 , P 3 can be used to describe their probabilities separately: reflecting the probability that the neutron is absorbed in the detection medium, and P 2 reflecting the charged particles ⁇ generated after the neutron is absorbed.
  • Equation 3 gives the reaction formula of neutron and 1 G B
  • Table 1 gives the charged particles after ⁇ Energy and its range in a typical medium B 4 C.
  • Fig. 1 schematically shows the emission process of alpha particles and 7 Li ions produced by the reaction of neutrons in a detection medium.
  • the neutron is injected into the detection medium and is absorbed by 1 Q B at a position in the medium (at the solid circle in Figure 1), releasing an a particle and a 7 Li ion, due to the large discharge energy of the reaction.
  • the kinetic energy of the system the emission of a and 7 Li is approximately 180 degrees backward, the thin and long arrow line in the figure is the track of a, and the short and thick arrow line is the track of 7 Li.
  • the exit directions of a and 7 Li are isotropic, and other different exit directions are also shown in Fig. 1.
  • the dotted circle in Figure 1 reflects the The maximum reachable range in the detection medium (eg B 4 C ). It can be seen from Fig.
  • the fan-shaped area in the probe medium in Figure 1 represents charged particles that cannot emit the detection medium. Due to the randomness of the ⁇ particle and the 7 Li ion direction, the fraction of the solid angle occupied by the sector in the whole unit sphere in Fig. 1 determines the probability that the charged particle cannot emit the detection medium, that is, the smaller the solid angle corresponding to the sector, Then P 2 is bigger (Note: Please imagine Figure 1 in 3D space).
  • the alpha particles and 7 Li have a range of several micrometers in a typical medium such as B 4 C, so the thickness of the probe medium in Figure 1 should not exceed a few microns. Considering that increasing the thickness will make P larger but reduce P 2 , so there should be a reasonable thickness range such that the total probability P obtained by equation (2) is larger.
  • the relationship between the thickness of the detecting medium and the detection efficiency shown in Fig. 2 can be obtained by calculation.
  • FIG. 2 shows a schematic diagram of such a technical solution for achieving higher detection efficiency using a multi-layered detection medium.
  • the detection medium (this thickness is usually between 0.5 and 1.7 micrometers, preferably 1 micrometer left for use as a detection medium; :, how to set more
  • the medium with the appropriate thickness is used to form the neutron detector.
  • the second factor involves the detection. The structural design of the device is not described in detail in this application. The factors of the first aspect of interest in this application will be discussed in depth below.
  • micron-sized neutron sensitive coatings for example, coatings containing 1 G B materials
  • the object of the present invention includes at least one of the following:
  • the neutron sensitive coating achieved by the invention has better surface flatness
  • the neutron sensitive coating achieved by the present invention has good adhesion so as not to fall off on the substrate;
  • the neutron sensitive coating achieved by the present invention has good stability and resistance to deliquescence.
  • the present invention provides a method of forming a neutron sensitive coating comprising: step a: placing at least one substrate in a reaction chamber;
  • Step b vacuuming the reaction chamber;
  • Step c feeding a first sensitive film precursor into the reaction chamber such that the first sensitive molecular film is formed, thereby forming a molecular film composed of molecules of the first sensitive film precursor, wherein The first sensitive film precursor contains neutron sensitive nuclide;
  • Step d feeding an inert rinsing agent that does not chemically react with the first sensitive film precursor into the reaction chamber to remove molecules of the first sensitive film precursor that are not adsorbed in the reaction chamber ;
  • Step e feeding another sensitive film precursor different from the first sensitive film precursor into the reaction chamber, so that the other sensitive film precursor and the newly formed molecule on the surface of the substrate a chemical reaction occurs in the membrane;
  • Step f feeding an inert rinsing agent that does not chemically react with the other sensitive film precursor into the reaction chamber to remove the chemical reaction between the reaction chamber and the molecular film on the surface of the substrate The molecule of the other sensitive membrane precursor;
  • Step g if there are other sensitive membrane precursors that need to be fed into the reaction chamber to chemically react with the just formed molecular film on the surface of the substrate, then for each other sensitive membrane precursor that has not yet been fed Repeat step e and step f;
  • Step h Steps c to g are repeated until the total thickness of the formed molecular films of each layer reaches a desired value, thereby forming a coating film containing neutron-sensitive nuclide.
  • the neutron sensitive nuclides are 1 Q B.
  • the first sensitive film precursor is BBr 3 .
  • the other sensitive film precursor is H 2 O or NH 3 .
  • the at least one substrate is a multi-layer planar substrate, and there is a spacing between the substrates of each layer.
  • the spacing is set such that the ratio of the length of the substrate of the at least one substrate to the spacing is in the range of from 2000: 1 to 40:1.
  • the method further comprises the following steps after the step h:
  • Step i feeding a first protective film precursor into the reaction chamber, so that molecules of the first protective film precursor are adsorbed on the existing molecular film on the surface of the substrate, thereby forming a layer a molecular film composed of molecules of a protective film precursor;
  • Step j feeding an inert rinsing agent that does not chemically react with the first protective film precursor into the reaction chamber to remove molecules of the first protective film precursor that are not adsorbed in the reaction chamber ;
  • Step k feeding another protective film precursor different from the first protective film precursor into the reaction chamber, so that the other protective film precursor and the newly formed molecule on the surface of the substrate a chemical reaction occurs in the membrane;
  • Step 1 feeding an inert rinsing agent that does not chemically react with the other protective film precursor into the reaction chamber to remove chemical reaction in the reaction chamber that does not react with the molecular film on the surface of the substrate The molecule of the other protective film precursor;
  • Step m if there are other protective film precursors that need to be fed into the reaction chamber to chemically react with the just formed molecular film on the surface of the substrate, then for each other protective film precursor that has not yet been fed Repeat step k and step 1;
  • Step n Steps i to m are repeated until the total thickness of each of the formed protective molecular films reaches another desired value, thereby forming a protective film to prevent devitrification or detachment of the coating containing the neutron sensitive nuclides.
  • the first protective film precursor is trimethyl aluminum.
  • the other protective film precursor is H 2 O or ozone.
  • the present invention provides a neutron sensitive coating comprising: a coating comprising a neutron sensitive nuclides;
  • a protective film on the plating film containing the neutron sensitive nuclides is provided, which protects the coating film containing the neutron sensitive nuclides from being damaged or degraded.
  • the neutron sensitive nuclides are 1Q B.
  • the coating film containing neutron sensitive species consists of B 2 O 3 or BN.
  • the protective film is composed of A1 2 0 3 .
  • Figure 1 schematically shows the alpha particles produced by the reaction of neutrons in the detection medium
  • Fig. 2 schematically shows the relationship between the thickness of the detecting medium and the detection efficiency.
  • Fig. 3 schematically shows a technical solution for realizing high detection efficiency using a multilayer detection medium.
  • Figure 4 is a schematic illustration of an apparatus for forming a neutron sensitive coating in which a plurality of substrates to be coated have been placed in a reaction chamber of the apparatus in accordance with a preferred embodiment of the present invention.
  • Figure 5 illustrates a side of a neutron sensitive coating formed in accordance with a preferred embodiment of the present invention. Schematic diagram of the core process of the law.
  • Figure 6 shows a schematic representation of the formation of a neutron sensitive coating on the surface of a substrate in accordance with a preferred embodiment of the present invention.
  • Figure 4 shows a schematic diagram of an apparatus 100 for forming a neutron sensitive coating in accordance with a preferred embodiment of the present invention.
  • the apparatus 100 for forming a neutron sensitive coating of the present invention can include a reaction chamber 110 in which a substrate 120 (preferably a planar substrate) has been provided.
  • Substrate 120 can be constructed of Al, Si, or other suitable materials.
  • the substrate 120 disposed in the reaction chamber 1 10 is preferably a plurality of layers with a certain spacing between the substrates of each layer so that a larger area of the neutron sensitive coating can be obtained in one operation. In the case where the substrates of the respective layers are equal in size, the spacing between the substrates of the respective layers is preferably equal.
  • the spacing between the layers of substrate is preferably determined based on the length of the substrate.
  • the pitch between the layers of the substrate may be set such that the ratio of the length of the substrate to the pitch of the substrate is in the range of from 2000:1 to 40:1.
  • the pitch between the layers of the substrate may be set such that the ratio of the length of the substrate to the pitch of the substrate is in the range of from 2000:1 to 40:1.
  • only one layer of substrate 120 may be disposed in the reaction chamber 10 10 without regard to the large inter-substrate problems between the substrates.
  • the apparatus 100 for forming a neutron sensitive coating of the present invention further includes at least a feedthrough 130 for feeding a sensitive membrane precursor into the reaction chamber 110, such as for each precursor and inert rinse.
  • a feedthrough 130 for feeding a sensitive membrane precursor into the reaction chamber 110 such as for each precursor and inert rinse.
  • the various sensitive film precursors may be fed into the reaction chamber 1 10 alternately by a single feed device, or a separate feed device may be provided for each of the sensitive film precursors.
  • two different sensitive film precursors are used, and a feedthrough 130 is provided separately for each sensitive film precursor.
  • the apparatus 100 for forming a neutron sensitive coating of the present invention further includes an outlet passage 140 having a valve for discharging excess precursor and reaction by-products from the reaction chamber 110 out of the reaction chamber 110.
  • outlet passage 140 having a valve for discharging excess precursor and reaction by-products from the reaction chamber 110 out of the reaction chamber 110.
  • other auxiliary devices are not shown in FIG.
  • a heating device for adjusting the operating temperature of the reaction chamber (the operation of the present invention is similar to performing chemical vapor deposition, and it is recognized in the art that The operating temperature in such a reaction chamber is controlled within a desired range, for example 200 - 300 ° C), a vacuuming device for forming a vacuum condition in the reaction chamber before feeding the substrate, and a control device for performing electrical control, etc., because these auxiliary devices are similar to the present
  • Corresponding devices in the chemical vapor deposition apparatus of the prior art are well known and readily implemented by those skilled in the art.
  • the method of forming a neutron sensitive coating of the present invention comprises the following steps: Step a: At least one substrate 120 is placed in the reaction chamber 110. Those skilled in the art will recognize that these substrates are preferably surface cleaned prior to being placed in the reaction chamber 1 10 .
  • Step b Vacuuming the reaction chamber U 0 .
  • Step c feeding the first sensitive film precursor into the reaction chamber 110, for example, through a feeding device 130, so that molecules of the first sensitive film precursor are adsorbed on the surface of the substrate, thereby forming a layer a molecular film composed of molecules of the first sensitive film precursor, wherein the first sensitive film precursor contains a neutron sensitive species.
  • the neutron sensitive nuclides which are preferably used in the present invention are 1 G B.
  • the available neutron-sensitive nuclides include 1 55 ' 157 Gd, 6 Li, and so on.
  • the first sensitive film precursor is preferably one containing one of these neutron sensitive species, particularly 1 Q B .
  • the various precursors should be in their gaseous form, at least in the reaction chamber. Further, it should be noted that the gaseous substance or gas mentioned in the present application is not required to be in a gaseous form at normal temperature as long as the substance is in a gaseous form in the reaction chamber.
  • Step d feeding an inert rinsing agent that does not chemically react with the first sensitive film precursor into the reaction chamber 110, for example, through a feeding device, to remove the unresorbed portion of the reaction chamber 1 10
  • the molecule of the first sensitive film precursor is preferably a gas purge using an inert gas as an inert rinse, and excess molecules of the first sensitive membrane precursor that are not adsorbed are blown out of the reaction chamber 1 10 through the outlet passage 140 to avoid these precursors and The precursor to be fed later reacts in space rather than the surface of the substrate.
  • the composition of the other sensitive film precursor is generally not particularly limited, and it is only required to be capable of reacting with the first sensitive step f: without reacting with the other sensitive film precursor.
  • 11 rinse For example, it is fed into the reaction chamber 1 10 through a feeding device to remove molecules of the other sensitive film precursor that are not chemically reacted with the molecular film on the surface of the substrate in the reaction chamber 1 10 .
  • This step is also preferably a gas purge using an inert gas as an inert rinse, and excess molecules of the other sensitive membrane precursor that are not adsorbed are blown out of the reaction chamber 1 through the outlet passage 140, so that the reaction chamber is no longer This precursor exists.
  • the inert rinsing materials used in step d and step f may be the same inert gas, although it is of course also possible to use different inert material gases.
  • Step g if there are other sensitive membrane precursors that need to be fed into the reaction chamber to chemically react with the just formed molecular film on the surface of the substrate, then for each other sensitive membrane precursor that has not yet been fed Repeat steps e and f.
  • two or more than two sensitive film precursors may be selected according to the needs of the chemical reaction to form a molecular film containing a neutron sensitive species. It is recognized by those skilled in the art based on well-known knowledge of chemical reactions.
  • this conditional step in the method of the present application is determined since the type of sensitive film precursor used is typically determined prior to the start of the operation. In actual operation, it does not mean that a conditional judgment is to be made here, but it may mean that the method of the present invention may or may not include this step depending on the specific circumstances.
  • Step h Steps C to g are repeated until the total thickness of the formed molecular films of the respective layers reaches a desired value, thereby forming a coating film containing neutron-sensitive nuclide stepwise or finally. It can be recognized that, when step C is repeated, the molecules of the first sensitive film precursor are adsorbed on the formed molecular film on the surface of the substrate, and are no longer directly adsorbed on the surface of the substrate (because A molecular film has been formed on the surface of the substrate by the previous steps).
  • the desired value of the total thickness of each of the formed molecular films may be any value in the range of 0.5 to 1.7 ⁇ m, preferably any value in the range of 0.8 to 1.2 ⁇ m, and more preferably about 1 ⁇ m.
  • step C to step g After a cycle such as step C to step g, a molecular film is formed on the surface of the substrate, and the thickness of the molecular film is on the order of A (determined by the height of the molecular layer), in order to achieve a micron-thickness coating, A lot of loops are needed. It should be noted here that the reason why the present application describes step h as "repeating steps c to g until the total thickness of the formed molecular films of each layer reaches the desired value" is because the cycle of steps C to g needs to be repeated.
  • the number of times is essentially determined by the desired value of the total thickness of the formed molecular films of each layer (the height of the molecular layer of the compound formed after the selection of various precursors is constant), and those skilled in the art can Understand that this description does not mean that it must be monitored in real time in practice. It is determined whether the total thickness of the formed molecular films of each layer reaches a desired value. On the contrary, it is preferred to calculate the number of times of repetition required according to the desired total thickness desired value and the height of the single molecular layer, and in the actual operation, steps C to g Repeat this number of times.
  • Figure 5 illustrates the core process of a preferred embodiment of the method of forming a neutron sensitive coating of the present invention.
  • two types of sensitive film precursors are selected, wherein the first sensitive film precursor fed in step c is preferably BBr 3 , and the other sensitive film precursor fed in step e is preferably H 2 0 Or NH 3 .
  • the first sensitive film precursor fed in step c is preferably BBr 3
  • the other sensitive film precursor fed in step e is preferably H 2 0 Or NH 3 .
  • the coating can be used as a final neutron sensitive coating, and its thickness uniformity, surface flatness, adhesion, etc. are relative to the prior art.
  • the coating has been greatly improved.
  • the adhesion and/or stability of such a coating may not be ideal, and there may be problems such as easy peeling and/or deliquescence.
  • the compound B 2 0 3 constituting the plating film reacts with water vapor to form boric acid, which affects the plating effect. Therefore, it is preferred to continue the treatment of the surface of this coating.
  • the present invention preferably continues to form a protective film (or passivation coating) on a coating containing neutron sensitive species using a process similar to steps c through c but using different precursors.
  • the process of forming a protective film specifically includes the following steps:
  • Step i feeding the first protective film precursor into the reaction chamber, for example, through a feeding device
  • the molecules of the first protective film precursor are adsorbed on the existing molecular film on the surface of the substrate to form a molecular film composed of molecules of the first protective film precursor.
  • the first protective film precursor may be tridecyl aluminum.
  • Step j feeding an inert rinsing agent that does not chemically react with the first protective film precursor into the reaction chamber 110 to remove the first protective film precursor that is not adsorbed in the reaction chamber molecule. Also, this step also preferably uses an inert gas as an inert rinse for gas flushing, and excess molecules of the first protective film precursor which are not adsorbed are blown out of the reaction chamber 110 through the gas outlet passage 140 to prevent the precursors and The precursor to be fed later reacts in space rather than the surface of the substrate
  • Step k feeding another protective film precursor different from the first protective film precursor into the reaction chamber 1 10, for example, through another feeding device 130, so that the other protection
  • the film precursor chemically reacts with the molecular film just formed on the surface of the substrate.
  • the another protective film precursor may be H 2 O or ozone, which chemically reacts with the adsorbed first protective film precursor to form a molecular film of A1 2 0 3 .
  • Step 1 feeding an inert rinsing agent that does not chemically react with the other protective film precursor into the reaction chamber 1 10 to remove the molecular film on the surface of the reaction chamber 110
  • the molecule of the other protective film precursor that undergoes a chemical reaction may be the same inert gas as in step d and step f, although it is also possible to use a different inert gas.
  • Step m if there are other protective film precursors that need to be fed into the reaction chamber to chemically react with the just formed molecular film on the surface of the substrate, then for each other protective film precursor that has not yet been fed Repeat steps k and 1.
  • two or more protective film precursors can be selected according to the needs of the chemical reaction to form a protective film, which is a person skilled in the art. Knowledge based on well-known chemical reactions can be easily implemented.
  • this conditional step j in the method of the present application is The actual operation does not mean that a conditional judgment is to be made here, but may mean that the method of the present invention may or may not include this step depending on the specific circumstances.
  • Step n repeating steps i to m until the total thickness of the formed protective molecular films reaches another desired value, thereby forming a protective film to prevent the coating containing the neutron-sensitive nuclide from appearing, for example, deliquescent or falling off.
  • the desired value of the total thickness of the protective layer of the protective layer ie, the thickness of the protective film
  • step n the reason why the present application describes step n as "repeating step i to step m until the total thickness of each layer of protective molecular film formed reaches another desired value" is because step i to step j
  • the number of times the cycle needs to be repeated is essentially determined by the other desired value of the total thickness of each layer of protective molecular film formed (the height of the molecular layer of the compound formed after the selection of various protective film precursors) It is certain), and those skilled in the art can understand that this description does not mean that the total thickness of the formed protective molecular films must be monitored in real time in practice. Whether the degree reaches another desired value, on the contrary, it is preferable to calculate the number of times of repetition required according to the other desired value and the height of a single molecular layer, and repeat the cycle of steps i to j in the actual operation.
  • a neutron-sensitive plating film 122 having a protective plating film 124 can be formed on the surface of the substrate.
  • the above method of the present invention achieves both a coating having a large thickness and a uniform thickness, and improves the stability of the coating and improves adhesion.
  • the coating achieved by this method the surface flatness of the coating will also be very good, on the order of A.
  • a large-area, high-efficiency thermal neutron detector can be fabricated.

Abstract

本发明涉及中子敏感镀膜及其形成方法。本发明的形成中子灵敏镀膜的方法主要包括：将第一敏感膜前驱体馈入反应腔中，使得第一敏感膜前驱体的分子被吸附在基材表面上，从而形成一层由该前驱体的分子构成的分子膜；在清除了反应腔中多余的前驱体后，将不同于第一敏感膜前驱体的另一敏感膜前驱体馈入反应腔中，以使所述另一敏感膜前驱体与基材表面上刚形成的分子膜发生化学反应；之后清除掉反应腔中多余的前驱体；如果还有其他需要馈入的敏感膜前驱体，则依次将其馈入进行反应，并清除多余的前驱体；重复上述馈入前驱体、清除多余前驱体的步骤，直到形成期望厚度的含有中子敏感核素的镀膜。

Description

中子敏感镀膜及其形成方法 技术领域
本发明一般性地涉及核技术应用中的中子探测技术， 具体地涉及 中子敏感镀膜及其形成方法。 背景技术
由于近年来 3He 气体供货短缺， 导致应用于中子散射、 国土安全 的中子探测器面临无气可用的困局。 为了解决因为 3He缺乏导致的问 题， 国际同行近来一直在研究破解这一问题的方法。 由于能够用于探 测中子的核素种类非常有限， 典型的核素有 3He、 6Li、 1 (1H和 155'157Gd 等。 而这其中 3He已经面临供货不足； 6Li则存在灵敏度低、 所形成的 探测介质不稳定的问题； 155'157Gd虽然灵敏度很高， 但是其产生的带电 粒子能量较低、 γ较多， 因此不利于中子信号的形成与高 η/γ抑制比的 实现。 综合来看， 以 1QB作为探测核素是目前最优的选择， 因而下面将 以重点以 1 QB为例进行描述。但是需要说明的是， 本领域技术人员均可 认识到，下面针对 1DB作为中子敏感核素讨论的问题对于 6Li和 155'157Gd 也同样存在， 而且本发明的技术方案也可适用于以 6Li和 155'157Gd作为 中子敏感核素的应用中。
由于 1 QB具有较高的热中子吸收截面 3836b@25.3meV， 其吸收中 子之后以 100 %的概率放出带电粒子、 且带电粒子能量较高 （为 2.3 1 MeV ), 产生的 γ射线能量较低 （为 478keV )， 这使得 1 ()B有可能 实现较高的探测效率和较好的 η/γ抑制比。
在实现中子测量的过程中， 通常需要三个步骤： 1 )探测介质吸收 中子； 2 ) 中子被探测介质中的 1QB核素吸收后放出带电粒子， 带电粒 子射出探测介质； 3 ) 射出探测介质的带电粒子在气体 （或固体表面） 中发生电离形成电子和离子， 这些电子和离子被探测器的阴极和阳极 收集形成信号。 对于这三个步骤， 可以用三个参数 P,、 P2、 P3来分别 描述其概率： 反映中子在探测介质中被吸收的概率， P2反映中子被 吸收后产生的带电粒子 α和 7Li射出探测介质的概率， P3反映射出探测 介质的带电粒子发生后续电离之后形成的可观测信号的概率。 中子探 测器总的探测效率 P由下式 （ 1 ) 决定： P = R x P, x P, ( 1 ) 一般而言， 带电粒子电离形成的信号经过后续放大 （探测器内在 的雪崩放大，或者电路放大），很容易被探测到， 因此 P3—般接近 100% 的效率， 于是式 （ 1 ) 可简化为：
( 2 ) 这样， 为了提高探测器的总体探测效率 P， 就需要提高
Figure imgf000004_0001
Ρ2， 但是这里 Ρ ^。 Ρ2存在竟争的关系——二者是此消彼长的。 为了使探测 介质对中子吸收的概率增大， 要求探测介质的厚度越大越好， 但是这 式 3给出了中子与 1 GB的反应式，表 1给出了^ ί之后带电粒子的 能量及其在典型介质 B4C 中的射程。 图 1 示意性地示出了中子在探测 介质中发生反应产生的 α粒子和 7Li离子的出射过程。
7L + a + 2.79MeV(6.1%)
n + wB→
Li' + a + 2.3 lMeV(93.9%) = (3837士 9)b
Figure imgf000004_0002
Figure imgf000004_0003
B与中子反应产物的能量及其在探测介质中的射程
Figure imgf000004_0004
在图 1 中， 中子射入探测介质， 在介质中的某个位置 （图 1 中的 实心圓处）被 1 QB吸收， 放出一个 a粒子和 7Li离子， 由于反应的放能 远远大于反应前系统的动能， a和 7Li的出射近似为 180度背向出射， 图中细而长的箭头线为 a的径迹示意，短而粗的箭头线为 7Li的径迹示 意。 另外， a和 7Li的出射方向是各向同性的， 图 1 中也给出了另外一 些不同的出射方向。 图 1 中的虚线圓反映了由 a粒子射程决定的其在 探测介质（例如 B4C ) 中的最大可及范围。 由图 1可以看出， 当带电粒 没有到达探测介质的边界， 因此带电粒子将无法射出探测介质， 从而 导致无法在探测介质之外的气体 （或固体表面） 形成电离， 致使无法 探测。 图 1 中探测介质内的扇形区域代表了无法射出探测介质的带电 粒子。 由于 α粒子和 7Li离子方向的随机性， 图 1 中扇形区域在整个单 位球中所占立体角的份额， 决定了带电粒子不能射出探测介质的概率， 即扇形区对应的立体角越小， 则 P2越大 （注意： 请以三维空间来想象 图 1 )。
如表 1 中的数据所示， α粒子和 7Li在 B4C这样典型的介质内的射 程在数微米， 因此图 1 中探测介质的厚度不应超过数微米。 综合考虑 增大厚度将使 P 大但使 P2减小， 因而应该存在一个较合理的厚度范 围， 使得由式 （2 )得到的总概率 P较大。 经过计算可得到图 2所示的 探测介质的厚度与探测效率的关系。
如图 2 所示， 随着探测介质厚度的增大， 探测效率也在增大， 但 是这个增大的过程具有饱和的趋势， 显示了 ？,增大的过程必然伴随着
Ρ2的减小。 由图 2也可以看出， 一味地增大厚度， 探测效率最大也仅 会在 12%左右， 这与一般中子探测器希望探测效率达到 50%以上的要 求相去甚远。 因此， 为了能够实现较高的探测效率， 必须采用多层中 子探测介质的方案， 而且每层中子探测介质的厚度不应太大， 应在 1 微米左右。 由图 2可以看出， 探测介质厚度优选为 1微米的原因在于 该厚度探测介质的饱和作用还不明显， 即厚度的增大对 Ρ2的影响还不 甚突出。 用单层 1微米的中子探测介质， 可以实现 9.3%@25.3meV的 探测效率。 因此， 在采用多层这样的探测介质后， 就可以实现更高的 探测效率。 图 3 示出了这种利用多层探测介质来实现更高探测效率的 技术方案的示意图。
为了实现图 3 所示的利用多层探测介质来实现较高的探测效率， 当的探测介质 （这个厚度通常为 0.5 ~ 1.7微米之间， 优选为 1微米左 用作探测介质； ：、 如何设置多 具有适当厚度的探^则介质来构成中子 探测器。 在上述两方面的考虑因素中， 第 2 方面的因素涉及的是探测 器的结构设计问题， 本申请对此不作详述。 下面将针对本申请所关心 的第 1方面的因素进行深入讨论。
为了获得良好的 1 微米厚度级的中子探测介质， 本领域技术人员 已经做了一定的工作， 目前的技术方案主要包括磁控溅射和电子束蒸 发两种。 这两种技术都是利用被加速的电子或者离子在靶材的表面进 行轰击， 使得靶材中的例如 1 原子或者 1 (1H4C分子离开靶材、 射向并 沉积在被镀膜的基材表面上。 通过不断的轰击与沉积， 在基材表面形 成期望的探测介质薄膜。 由于磁控溅射和电子束蒸发技术本身已经是 非常成熟的技术， 本申请对其不进行详细介绍。 在此， 需要讨论的是 这两种技术实现的镀膜效果。
根据本申请发明人的研究， 利用磁控溅射技术和电子束蒸发技术 虽然可以形成微米量级的中子灵敏镀膜 （例如含 1 GB材料的镀膜）， 但 是它们至少存在如下缺点：
1 ) 在大面积镀膜时， 无法保证镀膜的厚度一致性；
2 ) 镀膜的附着力存在不足， 会出现脱落的现象；
3 ) 所形成的镀膜在外界环境中会进一步损坏或退化， 例如发生潮 解变质。 发明内容
本发明的目的在于克服现有中子灵敏镀膜形成技术的至少一个缺 点并提供性能优良的中子灵敏镀膜。 也就是说， 本发明的目的包括以 下至少一项：
• 克服现有技术中镀膜厚度一致性不好的问题， 实现厚度一致性 好的中子灵敏镀膜；
· 使本发明实现的中子灵敏镀膜具有较好的表面平整度；
• 使本发明实现的中子灵敏镀膜具有良好的附着性， 以便附着在 基材上不发生脱落；
• 使本发明实现的中子灵敏镀膜具有较好的稳定性， 耐潮解变 质。
一方面， 本发明提供了一种形成中子灵敏镀膜的方法， 其包括： 步骤 a: 将至少一层基材置于反应腔中；
步骤 b : 对所述反应腔抽真空； 步骤 c: 将第一敏感膜前驱体馈入所述反应腔中， 使得所述第一敏 成的分子膜上， 从而形成一层由所述第一敏感膜前驱体的分子构成的 分子膜， 其中所述第一敏感膜前驱体中含有中子敏感核素；
步骤 d:将与所述第一敏感膜前驱体不发生化学反应的惰性沖洗物 馈入所述反应腔中， 以清除所述反应腔中没有被吸附的所述第一敏感 膜前驱体的分子；
步骤 e: 将不同于所述第一敏感膜前驱体的另一敏感膜前驱体馈入 所述反应腔中， 以使所述另一敏感膜前驱体与所述基材表面上刚形成 的分子膜发生化学反应；
步骤 f: 将与所述另一敏感膜前驱体不发生化学反应的惰性冲洗物 馈入所述反应腔中， 以清除所述反应腔中没有与所述基材表面上的分 子膜发生化学反应的所述另一敏感膜前驱体的分子；
步骤 g:如果还有需要馈入所述反应腔以与所述基材表面上刚形成 的分子膜发生化学反应的其他敏感膜前驱体， 那么针对每种尚未被馈 入的其他敏感膜前驱体重复步骤 e和步骤 f;
步骤 h: 重复步骤 c至步骤 g， 直到形成的各层分子膜的总厚度达 到期望值， 从而形成含有中子敏感核素的镀膜。
优选地， 所述中子敏感核素是 1 QB。
优选地， 所述第一敏感膜前驱体是 BBr3。
优选地， 所述另一敏感膜前驱体是 H20或 NH3。
优选地， 所述至少一层基材为多层平面基材， 各层基材之间存在 间距。
优选地， 所述间距被设置成使得所述至少一层基材的基材长度与 所述间距之比处于 2000: 1至 40: 1的范围内。
优选地， 所述方法在步骤 h之后还包括以下步骤：
步骤 i: 将第一保护膜前驱体馈入所述反应腔中， 使得所述第一保 护膜前驱体的分子被吸附基材表面上已有的分子膜上， 从而形成一层 由所述第一保护膜前驱体的分子构成的分子膜；
步骤 j : 将与所述第一保护膜前驱体不发生化学反应的惰性沖洗物 馈入所述反应腔中， 以清除所述反应腔中没有被吸附的所述第一保护 膜前驱体的分子； 步骤 k:将不同于所述第一保护膜前驱体的另一保护膜前驱体馈入 所述反应腔中， 以使所述另一保护膜前驱体与所述基材表面上刚形成 的分子膜发生化学反应；
步骤 1: 将与所述另一保护膜前驱体不发生化学反应的惰性沖洗物 馈入所述反应腔中， 以清除所述反应腔中没有与所述基材表面上的分 子膜发生化学反应的所述另一保护膜前驱体的分子；
步骤 m: 如果还有需要馈入所述反应腔以与所述基材表面上刚形 成的分子膜发生化学反应的其他保护膜前驱体， 那么针对每种尚未被 馈入的其他保护膜前驱体重复步骤 k和步骤 1;
步骤 n: 重复步骤 i至步骤 m， 直到形成的各层保护性分子膜的总 厚度达到另一期望值， 从而形成保护膜， 以防止所述含有中子敏感核 素的镀膜出现潮解变质或脱落。
优选地， 所述第一保护膜前驱体是三甲基铝。
优选地， 所述另一保护膜前驱体是 H20或臭氧。
另一方面， 本发明还提供了一种中子灵敏镀膜， 其包括： 含有中子敏感核素的镀膜； 以及
提供在所述含有中子敏感核素的镀膜上的保护膜， 其保护所述含 有中子敏感核素的镀膜不被损坏或退化。
优选地， 所述中子敏感核素是 1QB。
优选地， 所述含有中子敏感核素的镀膜由 B203或 BN构成。
优选地， 所述保护膜由 A1203构成。
附图说明
图 1 示意性地示出了中子在探测介质中发生反应产生的 α粒子和
7Li离子的出射过程。
图 2示意性地示出了探测介质的厚度与探测效率的关系。
图 3 示意性地示出了利用多层探测介质来实现高探测效率的技术 方案。
图 4 示出了根据本发明的一个优选实施例形成中子敏感镀膜的设 备的示意图， 在该设备的反应腔中已置入了多层待镀膜的基材。
图 5 示出了根据本发明的一个优选实施例形成中子敏感镀膜的方 法的核心过程的示意图。
图 6 示出了根据本发明一个优选实施例的方法在基材表面形成中 子敏感镀膜的示意图。 具体实施方式
图 4 示出了根据本发明的一个优选实施例形成中子敏感镀膜的设 备 100的示意图。 由图 4可以看出， 本发明用于形成中子敏感镀膜的 设备 100可包括反应腔 110， 该反应腔中已提供有基材 120 (优选为平 面基材）。 基材 120可以由 Al、 Si或其他合适的材料构成。 设置在反应 腔 1 10 中的基材 120优选为多层， 各层基材之间保持一定间距， 以便 可以在一次操作中获得更大面积的中子灵敏镀膜。 在各层基材大小相 等的情况下， 各层基材之间的间距优选是相等的。 设置该间距时， 既 希望该间距较小， 以便反应腔 1 10 能够容纳更多的基材， 同时还必须 保证这一较小间距不会影响成膜工艺的效果。 在本发明的一个实施例 中， 优选根据基材长度来确定各层基材之间的间距。 具体地， 可将各 层基材之间的间距设置成使得基材长度与基材间距之比处于 2000: 1 至 40: 1 之间的范围内。 当然， 本领域技术人员均可认识到， 在一个替代 性实施例中， 也可在反应腔 1 10仅设置一层基材 120， 这时不用考虑基 材之间的间 巨问题。
如图 4所示， 本发明用于形成中子敏感镀膜的设备 100还包括至 少用于将敏感膜前驱体馈入反应腔 1 10中的馈入装置 130，例如为每种 前驱体以及惰性沖洗物单独设置的各自带有阀门的馈入通道或带有外 部级联阀门的可交替地用于多种前驱体和 /或惰性沖洗物的共用型馈入 通道。 各种敏感膜前驱体可共用一个馈入装置交替地馈入反应腔 1 10 中， 也可为每种敏感膜前驱体单独设置一个馈入装置。 例如， 在图 4 所示的实施例中， 使用了两种不同的敏感膜前驱体， 而且为每种敏感 膜前驱体单独设置一个馈入装置 130。 此外， 本发明用于形成中子敏感 镀膜的设备 100还包括带有阀门的出气通道 140 ,用于将反应腔 1 10中 多余的前驱体和反应副产物排出反应腔 1 10。 为清楚起见， 图 4中并未 画出其它一些辅助装置， 例如用于调节反应腔工作温度的加热装置 (本 发明的操作过程类似于进行化学气相沉积， 本领域技术均可认识到通 常应将这种反应腔中的工作温度控制在一个期望的范围内， 例如 200 - 300°C )、用于在放入基材后馈入前驱体之前使反应腔中形成真空条 件的抽真空装置、 以及用于进行电气控制的控制装置等， 因为这些辅 助装置都类似于现有技术中化学气相沉积设备中的相应装置， 是本领 域技术人员熟知且容易实现的。
一般性地， 本发明的形成中子灵敏镀膜的方法包括以下步骤： 步骤 a: 将至少一层基材 120置于反应腔 1 10中。 本领域技术人员 均可认识到， 这些基材在放入反应腔 1 10 之前， 优选都是经过经过表 面清洗的。
步骤 b: 对反应腔 U 0抽真空。
步骤 c: 将第一敏感膜前驱体例如通过一个馈入装置 130馈入所述 反应腔 1 10 中， 使得所述第一敏感膜前驱体的分子被吸附在基材表面 上， 从而形成一层由所述第一敏感膜前驱体的分子构成的分子膜， 其 中所述第一敏感膜前驱体中含有中子敏感核素。 如前文所述， 本发明 中优选使用的中子敏感核素是 1 GB。 当然， 可用的中子敏感核素还包括 1 55' 157Gd、 6Li 等。 第一敏感膜前驱体优选为含有这些中子敏感核素之 一特别是含有 1 QB的物质。 本领域技术人员容易理解的是， 类似于化学 气相沉积技术， 在本发明中， 各种前驱体至少在反应腔中都应处于其 气态形式。 而且还要说明的是， 在本申请中提及的气态物质或气体均 不要求其在常温下也必须是气态形式的， 只要该物质在反应腔中为气 态形式即可。
步骤 d:将与所述第一敏感膜前驱体不发生化学反应的惰性冲洗物 例如通过馈入装置馈入所述反应腔 110 中， 以清除所述反应腔 1 10 中 没有被吸附的所述第一敏感膜前驱体的分子。 例如， 这一步骤优选是 使用惰性气体作为惰性冲洗物进行气体沖洗， 将多余的没有被吸附的 所述第一敏感膜前驱体的分子通过出气通道 140吹出反应腔 1 10 , 以免 这些前驱体和后面要馈入的前驱体在空间中而非基材表面发生反应。
步骤 将不同于所述第一敏感膜前驱体的另一敏感膜前驱体例如 通过馈入装置馈入所述反应腔 1 10 中， 以使所述另一敏感膜前驱体与 所述基材表面上刚形成的分子膜发生化学反应。 这里对所述另一敏感 膜前驱体的构成一般并不需要特别限定， 只要求其能够和所述第一敏 步骤 f: 将与所述另'一敏感膜前驱体不发 ^化学反应的惰性11沖洗物 例如通过馈入装置馈入所述反应腔 1 10 中， 以清除所述反应腔 1 10 中 没有与所述基材表面上的分子膜发生化学反应的所述另一敏感膜前驱 体的分子。 这一步骤同样是优选使用惰性气体作为惰性冲洗物进行气 体沖洗， 将多余的没有被吸附的所述另一敏感膜前驱体的分子通过出 气通道 140吹出反应腔 1 10， 使得反应腔内不再存在这一前驱体。 特别 地， 步骤 d和步骤 f中使用的惰性冲洗物可为相同的惰性气体， 当然选 用不同的惰性物质气体也是可行的。
步骤 g:如果还有需要馈入所述反应腔以与所述基材表面上刚形成 的分子膜发生化学反应的其他敏感膜前驱体， 那么针对每种尚未被馈 入的其他敏感膜前驱体重复步骤 e和步骤 f。 至此， 本领域技术人员均 可认识到， 在本发明的方法中， 可以根据化学反应的需要选用两种或 多于两种的敏感膜前驱体来形成含有中子敏感核素的分子膜， 这是本 领域技术人员根据公知的化学反应知识均能认识到的。 而且， 本领域 技术人员还可认识到， 对于本发明的方法而言， 由于所用的敏感膜前 驱体的种类通常是操作开始前就已确定的， 因此本申请方法中的这一 条件性步骤 g在实际操作中并不意味着要在此进行条件判断， 而是可 以意味着本发明的方法根据具体情况可以不进行或不包括这一步骤。
步骤 h : 重复步骤 C至步骤 g， 直到形成的各层分子膜的总厚度达 到期望值， 从而阶段性地或最终性地形成含有中子敏感核素的镀膜。 人们均可认识到， 在重复步骤 C 时， 所述第一敏感膜前驱体的分子是 被吸附在基材表面上已形成的分子膜上， 而不再是直接吸附在基材表 面上 （因为基材表面上已通过之前的步骤形成了一层分子膜）。 所形成 的各层分子膜的总厚度的期望值可为 0.5〜1.7微米范围内的任一值， 优 选地可为 0.8〜1.2微米范围内的任一值， 更优选地， 为 1微米左右。 经 过步骤 C至步骤 g这样一个循环之后， 在基材表面会形成一层分子膜， 该层分子膜的厚度在 A的量级（由分子层的高度决定）， 为了实现微米 级厚度的镀膜， 需要进行大量的循环。 在此需要说明的是， 本申请之 所以将步骤 h描述为 "重复步骤 c至步骤 g , 直到形成的各层分子膜的 总厚度达到期望值" 是因为步骤 C至步骤 g这一循环需要重复的次数 本质上是由所形成的各层分子膜的总厚度的期望值决定的 （选定了各 种前驱体后， 其生成的化合物的分子层的高度是一定的）， 而且本领域 技术人员均能理解， 这种描述并不意味着在实际操作中必须实时地监 测所形成的各层分子膜的总厚度是否达到期望值， 相反， 优选是根据 所需的总厚度期望值和单个分子层的高度计算出需要重复的次数， 并 在实际操作中将步骤 C至步骤 g重复该次数即可。
图 5 示出了本发明形成中子敏感镀膜的方法的一个优选实施例的 核心过程。 在图 5 中， 选用的敏感膜前驱体为两种， 其中步骤 c 中馈 入的第一敏感膜前驱体优选为 BBr3 , 步骤 e中馈入的另一敏感膜前驱 体优选为 H20或 NH3。 本领域技术人员均可认识到， 在本例中， 当步 骤 e中馈入的另一敏感膜前驱体为 H20时，其与第一敏感膜前驱体 BBr3 反应生成的是 B203 ,而当步骤 e中馈入的另一敏感膜前驱体为 NH3时， 其与第一敏感膜前驱体 BBr3反应生成的是 BN。
在完成了含有中子敏感核素的微米级厚度的镀膜之后， 该镀膜已 经可以作为最终的中子灵敏镀膜使用， 并且其厚度一致性、 表面平整 度、 附着性等都相对于现有技术的镀膜有很大改善。 不过， 这种镀膜 的附着性和 /或稳定性可能还不够理想， 其可能还会出现容易脱落和 / 或潮解变质等问题。 例如， 构成镀膜的化合物 B203会与水蒸气发生反 应生成硼酸， 影响镀膜效果。 因此， 优选还要对这一镀膜的表面继续 进行处理。
本发明优选用类似于步骤 c至步骤 h但使用了不同前驱体的过程 来继续在含有中子敏感核素的镀膜上形成保护膜 （或称钝化镀膜）。 形 成保护膜的过程具体包括如下步骤：
步骤 i : 将第一保护膜前驱体例如通过馈入装置馈入所述反应腔
1 10中，使得所述第一保护膜前驱体的分子被吸附基材表面上已有的分 子膜上， 从而形成一层由所述第一保护膜前驱体的分子构成的分子膜。 优选地， 所述第一保护膜前驱体可为三曱基铝。
步骤 j: 将与所述第一保护膜前驱体不发生化学反应的惰性沖洗物 馈入所述反应腔 110 中， 以清除所述反应腔中没有被吸附的所述第一 保护膜前驱体的分子。 同样， 这一步骤也优选使用惰性气体作为惰性 冲洗物进行气体沖洗， 将多余的没有被吸附的所述第一保护膜前驱体 的分子通过出气通道 140吹出反应腔 1 10, 以免这些前驱体和后面要馈 入的前驱体在空间中而非基材表面发生反应
步骤 k:将不同于所述第一保护膜前驱体的另一保护膜前驱体例如 通过另一个馈入装置 130馈入所述反应腔 1 10 中， 以使所述另一保护 膜前驱体与所述基材表面上刚形成的分子膜发生化学反应。 优选地， 所述另一保护膜前驱体可为 H20或臭氧， 其与被吸附的所述第一保护 膜前驱体发生化学反应形成 A1203的分子膜。
步骤 1: 将与所述另一保护膜前驱体不发生化学反应的惰性沖洗物 馈入所述反应腔 1 10 中， 以清除所述反应腔 110 中没有与所述基材表 面上的分子膜发生化学反应的所述另一保护膜前驱体的分子。 特别地， 步骤 j和步骤 i中使用的惰性沖洗物可为与步骤 d和步骤 f中相同的惰 性气体， 当然选用不同的惰性物质气体也是可行的，
步骤 m: 如果还有需要馈入所述反应腔以与所述基材表面上刚形 成的分子膜发生化学反应的其他保护膜前驱体， 那么针对每种尚未被 馈入的其他保护膜前驱体重复步骤 k和步骤 1。 本领域技术人员同样均 可认识到， 在本发明形成保护膜的过程中， 可以根据化学反应的需要 选用两种或多于两种的保护膜前驱体来形成保护膜， 这是本领域技术 人员根据公知的化学反应知识均能容易实施的。 而且， 本领域技术人 员还可认识到， 对于本发明的方法而言， 由于所用保护膜前驱体的种 类通常是操作开始前就可确定的， 因此本申请方法中的这一条件性步 骤 j在实际操作中并不意味着要在此进行条件判断，而是可以意味着本 发明的方法根据具体情况可以不进行或不包括这一步骤。
步骤 n: 重复步骤 i至步骤 m， 直到形成的各层保护性分子膜的总 厚度达到另一期望值， 从而形成保护膜， 以防止所述含有中子敏感核 素的镀膜出现例如潮解变质或脱落等问题。 所形成的各层保护性分子 膜的总厚度 （即保护膜厚度） 的期望值可为 1 ~ 100纳米范围内的任一 值， 优选地可为 8〜15纳米微米范围内的任一值， 更优选地， 为 10纳 米左右。 经过步骤 i至步骤 j这样一个循环后， 会形成一层分子膜， 该 层分子膜的厚度在 A的量级（由相应分子层的高度决定）， 为了实现纳 米级厚度的镀膜， 需要进行多次循环。 在此需要说明的是， 本申请之 所以将步骤 n描述为 "重复步骤 i至步骤 m , 直到形成的各层保护性分 子膜的总厚度达到另一期望值"是因为步骤 i至步骤 j这一循环需要重 复的次数本质上是由所形成的各层保护性分子膜的总厚度的所述另一 期望值决定的 （选定了各种保护膜前驱体后， 其生成的化合物的分子 层的高度是一定的）， 而且本领域技术人员均能理解， 这种描述并不意 味着在实际操作中必须实时地监测所形成的各层保护性分子膜的总厚 度是否达到了另一期望值， 相反， 优选是根据所述另一期望值和单个 分子层高度计算出需要重复的次数， 并在实际操作中将步骤 i至步骤 j 这一循环重复该次数即可。
经过前述的步骤之后， 如图 6 所示， 就可在基材表面上形成带有 保护性镀膜 124的中子敏感镀膜 122。本发明的上述方法既实现了大面 积厚度一致的镀膜， 又保护了镀膜的稳定性， 提高了附着性。 通过这 种方法实现的镀膜， 镀膜的表面平整度也会很好， 在 A的量级。 以这 种带有中子敏感镀膜的基材为基础， 就可以制造大面积、 高效率的热 中子探测器。

Claims

1 . 一种形成中子灵敏镀膜的方法， 其特征在于所述方法包括以下 步骤：
步骤 a: 将至少一层基材置于反应腔中；
步骤 b: 对所述反应腔抽真空；
步骤 c : 将第一敏感膜前驱体馈入所述反应腔中， 使得所述第一敏 成的分子膜上， 从而形成一层由所述第一敏感膜前驱体的分子构成的 分子膜， 其中所述第一敏感膜前驱体中含有中子敏感核素；
步骤 d:将与所述第一敏感膜前驱体不发生化学反应的惰性沖洗物 馈入所述反应腔中， 以清除所述反应腔中没有被吸附的所述第一敏感 膜前驱体的分子；
步骤 e: 将不同于所述第一敏感膜前驱体的另一敏感膜前驱体馈入 所述反应腔中， 以使所述另一敏感膜前驱体与所述基材表面上刚形成 的分子膜发生化学反应；
步骤 f: 将与所述另一敏感膜前驱体不发生化学反应的惰性沖洗物 馈入所述反应腔中， 以清除所述反应腔中没有与所述基材表面上的分 子膜发生化学反应的所述另一敏感膜前驱体的分子；
步骤 g:如果还有需要馈入所述反应腔以与所述基材表面上刚形成 的分子膜发生化学反应的其他敏感膜前驱体， 那么针对每种尚未被馈 入的其他敏感膜前驱体重复步骤 e和步骤 f;
步骤 h: 重复步骤 c至步骤 g , 直到形成的各层分子膜的总厚度达 到期望值， 从而形成含有中子敏感核素的镀膜。
2. 如权利要求 1 所述的方法， 其特征在于， 所述中子敏感核素是 B。
3. 如权利要求 2所述的方法， 其特征在于， 所述第一敏感膜前驱 体是 BBr3。
4. 如权利要求 3所述的方法， 其特征在于， 所述另一敏感膜前驱 体是 H2()或 NH3。
5. 如权利要求 1 所述的方法， 其特征在于， 所述至少一层基材为 多层平面基材， 各层基材之间存在间距。
6. 如权利要求 5所述的方法， 其特征在于， 所述间距被设置成使 得所述至少一层基材的基材长度与所述间距之比处于 2000: 1至 40: 1的 范围内。
7. 如权利要求 1所述的方法， 其特征在于， 所述方法在步骤 h之 5 后还包括以下步骤：
步骤 i: 将第一保护膜前驱体馈入所述反应腔中， 使得所述第一保 护膜前驱体的分子被吸附基材表面上已有的分子膜上， 从而形成一层 由所述第一保护膜前驱体的分子构成的分子膜；
步骤 j : 将与所述第一保护膜前驱体不发生化学反应的惰性沖洗物0 馈入所述反应腔中， 以清除所述反应腔中没有被吸附的所述第一保护 膜前驱体的分子；
步骤 k:将不同于所述第一保护膜前驱体的另一保护膜前驱体馈入 所述反应腔中， 以使所述另一保护膜前驱体与所述基材表面上刚形成 的分子膜发生化学反应；
5 步骤 1: 将与所述另一保护膜前驱体不发生化学反应的惰性沖洗物 馈入所述反应腔中， 以清除所述反应腔中没有与所述基材表面上的分 子膜发生化学反应的所述另一保护膜前驱体的分子；
步骤 m: 如果还有需要馈入所述反应腔以与所述基材表面上刚形 成的分子膜发生化学反应的其他保护膜前驱体， 那么针对每种尚未被0 馈入的其他保护膜前驱体重复步骤 k和步骤 1;
步骤 n: 重复步骤 i至步骤 m， 直到形成的各层保护性分子膜的总 厚度达到另一期望值， 从而形成保护膜， 以防止所述含有中子敏感核 素的镀膜出现潮解变质或脱落。
8. 如权利要求 7所述的方法， 其特征在于， 所述第一保护膜前驱 体是三曱基铝。
9. 如权利要求 8所述的方法， 其特征在于， 所述另一保护膜前驱 体是 H2()或臭氧。
10. 一种中子灵敏镀膜， 其特征在于所述中子灵敏镀膜包括： 含有中子敏感核素的镀膜； 以及
0 提供在所述含有中子敏感核素的镀膜上的保护膜， 其保护所述含 有中子敏感核素的镀膜不被损坏或退化。
1 1 . 如权利要求 10所述的中子灵敏镀膜， 其特征在于， 所述中子 敏感核素是 I GB。
12. 如权利要求 11 所述的中子灵敏镀膜， 其特征在于， 所述含有 中子敏感核素的镀膜由 B203或 BN构成。
13. 如权利要求 10所述的中子灵敏镀膜， 其特征在于， 所述保护 膜由 Λ1203构成。
14. 一种中子灵敏镀膜， 其特征在于， 所述中子灵敏镀膜由权利要 求 1 - 9中任一项所述的方法制成。
PCT/CN2012/001608 2011-12-19 2012-11-30 中子敏感镀膜及其形成方法 WO2013091280A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN2011104262565A CN103160799A (zh) 2011-12-19 2011-12-19 中子敏感镀膜及其形成方法
CN201110426256.5 2011-12-19

Publications (1)

Publication Number Publication Date
WO2013091280A1 true WO2013091280A1 (zh) 2013-06-27

Family

ID=48584326

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2012/001608 WO2013091280A1 (zh) 2011-12-19 2012-11-30 中子敏感镀膜及其形成方法

Country Status (2)

Country Link
CN (1) CN103160799A (zh)
WO (1) WO2013091280A1 (zh)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3339482A1 (en) 2016-12-26 2018-06-27 Nuctech Company Limited Sensitive film for neutron detection and method for forming the same
CN112725764A (zh) * 2020-12-18 2021-04-30 松山湖材料实验室 中子吸收材料及其制备方法和应用

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01164071A (ja) * 1987-12-21 1989-06-28 Fuji Electric Corp Res & Dev Ltd 半導体中性子線検出素子の製造方法
JPH10325877A (ja) * 1997-05-26 1998-12-08 Fuji Electric Co Ltd 半導体中性子線検出素子
KR100489300B1 (ko) * 2002-12-23 2005-05-17 재단법인 포항산업과학연구원 진공증착에 의한 중성자 검출용 후막 제조방법 및 그후막을 포함하는 중성자 검출용 금속판
JP2005286245A (ja) * 2004-03-30 2005-10-13 Japan Science & Technology Agency 超伝導素子、それを用いた中性子検出装置及び超伝導素子の製造方法
CN101171530A (zh) * 2005-03-07 2008-04-30 独立行政法人科学技术振兴机构 中子检测装置和中子成像传感器
US20110095193A1 (en) * 2009-10-26 2011-04-28 Finphys Oy Ultra thin neutron detector, method for manufacturing the neutron detector and neutron imaging apparatus
US20110233420A1 (en) * 2010-03-23 2011-09-29 Feller W Bruce Neutron Detection
CN102313898A (zh) * 2010-06-30 2012-01-11 清华大学 热中子探测器及其制造方法
US20120187305A1 (en) * 2011-01-21 2012-07-26 Uchicago Argonne Llc Microchannel plate detector and methods for their fabrication
CN202404247U (zh) * 2011-12-28 2012-08-29 同方威视技术股份有限公司 一种快中子探测器

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070084406A1 (en) * 2005-10-13 2007-04-19 Joseph Yudovsky Reaction chamber with opposing pockets for gas injection and exhaust
US20070259111A1 (en) * 2006-05-05 2007-11-08 Singh Kaushal K Method and apparatus for photo-excitation of chemicals for atomic layer deposition of dielectric film
US20090004405A1 (en) * 2007-06-29 2009-01-01 Applied Materials, Inc. Thermal Batch Reactor with Removable Susceptors
DE102008034330A1 (de) * 2008-07-23 2010-01-28 Ionbond Ag Olten CVD-Reaktor zur Abscheidung von Schichten aus einem Reaktionsgasgemisch auf Werkstücken

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01164071A (ja) * 1987-12-21 1989-06-28 Fuji Electric Corp Res & Dev Ltd 半導体中性子線検出素子の製造方法
JPH10325877A (ja) * 1997-05-26 1998-12-08 Fuji Electric Co Ltd 半導体中性子線検出素子
KR100489300B1 (ko) * 2002-12-23 2005-05-17 재단법인 포항산업과학연구원 진공증착에 의한 중성자 검출용 후막 제조방법 및 그후막을 포함하는 중성자 검출용 금속판
JP2005286245A (ja) * 2004-03-30 2005-10-13 Japan Science & Technology Agency 超伝導素子、それを用いた中性子検出装置及び超伝導素子の製造方法
CN101171530A (zh) * 2005-03-07 2008-04-30 独立行政法人科学技术振兴机构 中子检测装置和中子成像传感器
US20110095193A1 (en) * 2009-10-26 2011-04-28 Finphys Oy Ultra thin neutron detector, method for manufacturing the neutron detector and neutron imaging apparatus
US20110233420A1 (en) * 2010-03-23 2011-09-29 Feller W Bruce Neutron Detection
CN102313898A (zh) * 2010-06-30 2012-01-11 清华大学 热中子探测器及其制造方法
US20120187305A1 (en) * 2011-01-21 2012-07-26 Uchicago Argonne Llc Microchannel plate detector and methods for their fabrication
CN202404247U (zh) * 2011-12-28 2012-08-29 同方威视技术股份有限公司 一种快中子探测器

Also Published As

Publication number Publication date
CN103160799A (zh) 2013-06-19

Similar Documents

Publication Publication Date Title
JP6138686B2 (ja) ナノダイヤモンド層を有する電子増倍装置
CN105492653B (zh) 透明导电性膜及其制造方法
Bortolon et al. Observations of wall conditioning by means of boron powder injection in DIII-D H-mode plasmas
US8565364B2 (en) Water based dispersions of boron or boron compounds for use in coating boron lined neutron detectors
WO2013091280A1 (zh) 中子敏感镀膜及其形成方法
Morenzoni Physics and applications of low energy muons
Liu et al. Anomalous positive ion formation in negative ion collisions with HOPG
RU183457U1 (ru) Двухкоординатный тонкопленочный газонаполненный детектор тепловых и холодных нейтронов
WO2012000158A1 (zh) 热中子探测器及其制造方法
Nappi CsI RICH detectors in high energy physics experiments
CN106460153B (zh) 透明导电性膜及其制造方法
JP6843947B2 (ja) イオン発生複合ターゲット及びそれを使用したレーザー駆動イオン加速装置
WO2013141400A1 (ja) 電子増幅用細孔ガラスプレートおよび検出器
Verkhoturov et al. “Trampoline” ejection of organic molecules from graphene and graphite via keV cluster ions impacts
Guo et al. Unexpected Negative-Ion Conversion in Grazing Scattering of Negative Ions on HOPG
Gillich et al. Enhanced pyroelectric crystal D–D nuclear fusion using tungsten nanorods
Clifft et al. Backward photoproduction of ϱ° and f between 2.8 GeV and 4.8 GeV
JP5275356B2 (ja) 分析工程からスパッタリング工程を分離することによる有機及び無機の試料の定量的調査を可能にする方法及び装置
Lian et al. Effect of atmospheric environment on the stability of secondary electron emission from magnesium oxide and alumina surfaces
Variale Neutron Imager and Flux Monitor Based on Micro Channel Plates (MCP) in Electrostatic Mirror Configuration
Heiland Interaction of Low-Energy Ions, Atoms and Molecules with Surfaces
Khan et al. Preliminary results of fission induced by (1068 MeV) π− in Cu, Sn, Au and Bi using CR-39 detectors
Le Pimpec A Continuing Story on the Secondary Electron Yield Measurements of TiN Coating and TiZrV Getter Film
Ying et al. Changes in Work Functions of Vacuum Distilled Gold Films
Wei et al. Detection of alpha particles and low energy gamma rays by thermo-bonded Micromegas in xenon gas

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12859335

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12859335

Country of ref document: EP

Kind code of ref document: A1