CAJ | 학술논문

超高纯气体在工业生产中有非常重要的地位，如半导体工业中电子气的质量直接影响半导体器件的性能，百万分之几的微量杂质气体便可导致集成电路中元件存储信息量的减少。越来越高的气体纯度要求对分析方法及仪器的灵敏度提出了很大的挑战。大气压电离质谱（APIMS ）由于可以在大气压条件下对杂质进行电离，并伴随高效的电离方式，因此具有极高的灵敏度，成为超高纯气体杂质分析中极为有效的技术手段，特别适合检测10－9 mol／mol甚至10－12 mol／mol浓度量级的气体杂质。APIMS采用电晕放电及63 Ni两种电离源，通常以电晕放电电离源为主，质量分析器常采用四极杆，同时为适应超高纯气体分析，配备了气体进样系统及可将标准气体稀释产生校正气体的稀释系统。APIMS对杂质检测的灵敏度与杂质的电离方式密切相关，电荷传递是杂质电离最主要的一种方式，适用于电离能相差较大的底气与杂质，常见的N2、Ar由于电离能较高，其中的大部分杂质均可依靠该方式测定；质子转移反应的应用通常与H2有关，常用于H2中杂质的测定，也可以通过添加H2的方法促进对Ar中N2杂质的检测；运用形成团簇离子的反应尽管较少，但亦有报道，通过监测团簇离子O2＋·H2 O，可提高O2中杂质H2 O的检测灵敏度。APIMS依据不同的电离反应，可以设计不同杂质的测定方式，实现对痕量、超痕量杂质的检测，检测灵敏度通常比电子轰击电离质谱（EI-MS）高104～106倍，因此目前依然是超高纯气体分析中不可替代的仪器方法，但在某些方面如对腐蚀性电子特气的分析，方法灵敏度有待提高。
초고순기체재공업생산중유비상중요적지위，여반도체공업중전자기적질량직접영향반도체기건적성능，백만분지궤적미량잡질기체편가도치집성전로중원건존저신식량적감소。월래월고적기체순도요구대분석방법급의기적령민도제출료흔대적도전。대기압전리질보（APIMS ）유우가이재대기압조건하대잡질진행전리，병반수고효적전리방식，인차구유겁고적령민도，성위초고순기체잡질분석중겁위유효적기술수단，특별괄합검측10－9 mol／mol심지10－12 mol／mol농도량급적기체잡질。APIMS채용전훈방전급63 Ni량충전리원，통상이전훈방전전리원위주，질량분석기상채용사겁간，동시위괄응초고순기체분석，배비료기체진양계통급가장표준기체희석산생교정기체적희석계통。APIMS대잡질검측적령민도여잡질적전리방식밀절상관，전하전체시잡질전리최주요적일충방식，괄용우전리능상차교대적저기여잡질，상견적N2、Ar유우전리능교고，기중적대부분잡질균가의고해방식측정；질자전이반응적응용통상여H2유관，상용우H2중잡질적측정，야가이통과첨가H2적방법촉진대Ar중N2잡질적검측；운용형성단족리자적반응진관교소，단역유보도，통과감측단족리자O2＋·H2 O，가제고O2중잡질H2 O적검측령민도。APIMS의거불동적전리반응，가이설계불동잡질적측정방식，실현대흔량、초흔량잡질적검측，검측령민도통상비전자굉격전리질보（EI-MS）고104～106배，인차목전의연시초고순기체분석중불가체대적의기방법，단재모사방면여대부식성전자특기적분석，방법령민도유대제고。
Ultra high purity (UHP)gases are very important in the manufacturing industry.As an example,in the semiconductor industry,the quality of electron gas directly affects the performance of semiconductor devices;a few parts per million of trace impurities in gases can reduce component store information in integrated circuits.Thus, challenges to the sensitivity of the analytical instruments and the analysis methods arise for detection of ultra-trace impurities.Atmospheric Pressure Ionization Mass Spectrometry (APIMS),which could ionize impurities under the atmospheric pressure conditions with high efficiency of ionization and sensitivity,becomes the most important instrument for the purity analysis of the UHP gases.APIMS is especially suitable for the analysis of trace impurities with a concentration below 1 0 -9 mol/mol or even 1 0 -1 2 mol/mol.Two ionization sources based on corona discharge and 63 Ni have been developed for APIMS,where the former is more commonly equipped.Quadruple rod is usually used as the mass filter.A sampling and dilution system,in which the components in standard gas can be diluted to far lower concentrations for calibration,is utilized in APIMS for analysis of UHP gases.The detection sensitivity of impurities by APIMS is quite relevant to the ionization modes.One of the main modes is charge transfer reaction, which is applicable to matrix and impurities with large different ionization energy.For example,most impurities in Ar and N2 can be determined by this mode due to the high ionization energy of Ar and N2 .And by adding H2 , APIMS is also used for detecting N2 in Ar.The third mode is the reaction of forming cluster ions,for which few applications have been reported.The mode could enhance the detection sensitivity of H2 O in matrix O2 by detecting the ion of O2 +·H2 O.Based on these ionization modes,various detecting methods for different impurities can be designed to effectively detect trace or ultra-trace impurities.The sensitivity of APIMS is usually 1 04 -1 06 times higher than Electron Impact-Mass Spectrometry (EI-MS ).As a result,APIMS is still irreplaceable in UHP gas analysis,however,methods such as those required for the analysis of corrosive electronic special gases,should see an improvement in the sensitivity.