Radiation compatibility of thin layer resistors in integrated technology

U radu se razmatra dejstvo nuklearnog i elektromagnetnog zračenja na tanke izolacione slojeve koji su presudni u odvajanju elektronskih komponenti i struktura u višeslojnim gusto pakovanim integrisanim kolima. Naime, smanjenje debljine aktivnih i pasivnih slojeva integrisanih kola čini iste veoma osetljivim na dejstvo jonizujućeg zračenja i pojave prenapona atmosferskog i komutacionog porekla. Paralelno sa proizvodnjom takvih elektronskih kola razvoj tehnologije je doveo do povećanja nuklearne i elektromagnetne kontaminacije životne sredine. Istovremena pojava tankih višeslojnih elektronskih kola i nuklearne kontaminacije rezultirala je sinergijom koja je ograničila dalju minimizaciju elektronskih komponenti i sklopova postavivši jasnu granicu do koje ona može da ide. U pogledu dejstva nuklearnog zračenja i prenapona posebno je nepoželjan efekat koji može da dovede do proboja tankih izolacionih struktura. Takav efekat dovodi do kratkog spajanja elektronskih sklopova i komponenata čime se u potpunosti uništava višeslojno gusto pakovano integrisano kolo kao i ukupan sistem u koji je to kolo ugrađeno. Posebno nepovoljna situacija je kada se dejstvom jonskog zračenja stvori veće oštećenje u izolacionom sloju koje onda probiju i prenaponi submilivoltnog intenziteta, tj. kada dođe do sinergije između mehanički razarajućeg dejstva jonskog zračenja i električnog razaranja brzih prenaponskih pojava. Da bi se dobila slika o pouzdanosti komercijalnih električnih višeslojno integrisanih elektronskih komponenti u polju jonskog zračenja u ovom radu se opredelilo za numericki eksperiment primenom metode Monte Karlo. Pri tome je izabran optimalan generator slučajnih brojeva i napravljen je model ispitujućeg višeslojnog integrisanog kola pogodan za primenu postavljenog numeričkog eksperimenta. Realni eksperiment, koji je lakše izvodljiv, je izbegnut pošto se njime dobija integralna radijaciona kompatibilnost, a ne i diferencijalna, kao u slučaju numeričkog eksperimenta. Monte Karlo simulacije transporta protona kroz tanke slojeve SiO2, AlN, Al2O3 i polikarbonata su pokazali da su navedeni slojevi imuni na prolazak protona sa energijama većim od ∼10 MeV. Nejonizujući gubici energije ovih visokoenergetskih protona su mali i oni prolaze kroz slojeve bez mnogo atomskog rasejavanja. U donjem delu istraženog opsega protonske energije (od 10 keV do 1 MeV), treba očekivati značajne gubitke jonizacije. Jonizacija i oštećenja uzrokovana pomeranjima usled prolaska protona mogu uticati na svojstva pomenutih izolatora i ugroziti njihovu pouzdanost u složenim sklopovima i uređajima. Tačkasti defekti, od kojih su neki donori nosača naelektrisanja, nastaju u ozračenim izolatorima kao rezultat pomeranja (dislokacije) atoma. Visoko reaktivni slobodni radikali koji se mogu pojaviti u ozračenom leksanu izazivaju cepanje lanca i/ili umrežavanje, što utiče na izolaciona svojstva polikarbonatnih slojeva.The doctoral dissertation discusses the effect of nuclear and electromagnetic radiation on thin insulating layers that are crucial in the separation of electronic components and structures in multilayer densely packed integrated circuits. The thickness reducing of the active and passive layers of integrated circuits makes them very sensitive to the effects of ionizing radiation and the occurrence of overvoltages of atmospheric and commutation origin. In parallel with the production of such electronic circuits, the development of technology has led to an increase in nuclear and electromagnetic environmental contamination. The simultaneous emergence of thin multilayer electronic circuits and nuclear contamination has resulted in synergies that have limited further minimization of electronic components and assemblies by setting a clear limit to which it can go. With regard to the effects of nuclear radiation and overvoltage, the effect that can lead to the breakthrough of thin insulating structures is particularly undesirable. Such an effect leads to a short circuit of electronic assemblies and components, which completely destroys the multilayer densely packed integrated circuit as well as the overall system in which the circuit is installed. A particularly unfavorable situation is when the action of ion radiation creates greater damage in the insulating layer, which then breakthrough even overvoltages of submilivolt intensity, ie. when there is a synergy between the mechanically destructive effect of ion radiation and the electrical destruction of rapid surges. In order to obtain a picture of the reliability of commercial electrical multilayer integrated electronic components in the field of ion radiation, in this doctoral dissertation we decided on a numerical experiment using the Monte Carlo method. In doing so, the optimal random number generator was chosen and a model of the test multilayer integrated circuit suitable for the application of the set numerical experiment was made. A real experiment, which is easier to perform, is avoided because it gives integral radiation compatibility, and not differential, as in the case of a numerical experiment. Monte Carlo simulations of proton transport through thin layers of SiO2, AlN, Al2O3 and polycarbonate have shown that the investigated layers are immune to the passage of protons with energies higher than ∼10 MeV. Nonionizing energy loss of these high energy protons is low, and they traverse the layers without much atomic displacement. In the lower part of the investigated proton energy range (from 10 keV to 1 MeV), however, substantial ionization losses are to be expected. Ionization and displacement damage produced by protons could influence the properties of these insulators and compromise their reliability within complex structures and devices. Point defects, some of which are charge-carrier donors, arise in irradiated insulators as a result of atomic displacements. Highly reactive free radicals that can appear in irradiated lexan cause chain scission and/or cross-linking, which then affects the insulating properties of polycarbonate layers

Simulation-based calculations of the proton dose in phase change memory cells

Monte Carlo simulations of proton irradiation on phase change memory cells were conducted and the proton dose, in both the whole memory cell and in its active layer, calculated. The memory cell was modeled by a multi-layer stack consisting of two TiW electrodes and ZnS-SiO2 films as insulators surrounding the active region. Materials considered for the active region were Ge2Sb2Te5, AgSbSe2, and Si2Sb2Te5. The effects of exposing phase change memory cells to proton beams were investigated for various thicknesses of phase change materials and different proton energies. Radiation-induced changes in the investigated memory cells are presented, including the accumulation of atomic displacements and the thermal heating of the active region. Possible effects of these changes on cell operation are discussed. [Projekat Ministarstva nauke Republike Srbije, br. 171007

Possibility of achieving an acceptable response rate of gas-filled surge arresters by substitution of alpha radiation sources by selection of electrode material and the electrode surface topography

The possibility of substituting the usage of a radioactive a-source to improve the characteristics of the gas surge arrester is considered in this paper. The solution to this problem is sought in the engineering of the characteristics by applying different electrode materials and varying electrode surface topography. Materials that differ in the output work value were examined. The electrode surface topographies were either polished, or with engraved regular spikes, or with polished cavities. The paper is mostly experimental in nature. The experiments were performed under well-controlled laboratory conditions. The measurement uncertainty of the experimental procedure was satisfactory. Experimental results were processed by sophisticated statistical methods of low statistical unreliability. The obtained results show that it is possible to avoid the installation of a radioactive source in the gas surge arresters and how it should be done. In this way, a possible contamination of the natural environment with extremely dangerous alpha - radioactive sources would be avoided

Radiation compatibility of thin layer resistors in integrated technology

U radu se razmatra dejstvo nuklearnog i elektromagnetnog zračenja na tanke izolacione slojeve koji su presudni u odvajanju elektronskih komponenti i struktura u višeslojnim gusto pakovanim integrisanim kolima. Naime, smanjenje debljine aktivnih i pasivnih slojeva integrisanih kola čini iste veoma osetljivim na dejstvo jonizujućeg zračenja i pojave prenapona atmosferskog i komutacionog porekla. Paralelno sa proizvodnjom takvih elektronskih kola razvoj tehnologije je doveo do povećanja nuklearne i elektromagnetne kontaminacije životne sredine. Istovremena pojava tankih višeslojnih elektronskih kola i nuklearne kontaminacije rezultirala je sinergijom koja je ograničila dalju minimizaciju elektronskih komponenti i sklopova postavivši jasnu granicu do koje ona može da ide. U pogledu dejstva nuklearnog zračenja i prenapona posebno je nepoželjan efekat koji može da dovede do proboja tankih izolacionih struktura. Takav efekat dovodi do kratkog spajanja elektronskih sklopova i komponenata čime se u potpunosti uništava višeslojno gusto pakovano integrisano kolo kao i ukupan sistem u koji je to kolo ugrađeno. Posebno nepovoljna situacija je kada se dejstvom jonskog zračenja stvori veće oštećenje u izolacionom sloju koje onda probiju i prenaponi submilivoltnog intenziteta, tj. kada dođe do sinergije između mehanički razarajućeg dejstva jonskog zračenja i električnog razaranja brzih prenaponskih pojava. Da bi se dobila slika o pouzdanosti komercijalnih električnih višeslojno integrisanih elektronskih komponenti u polju jonskog zračenja u ovom radu se opredelilo za numericki eksperiment primenom metode Monte Karlo. Pri tome je izabran optimalan generator slučajnih brojeva i napravljen je model ispitujućeg višeslojnog integrisanog kola pogodan za primenu postavljenog numeričkog eksperimenta. Realni eksperiment, koji je lakše izvodljiv, je izbegnut pošto se njime dobija integralna radijaciona kompatibilnost, a ne i diferencijalna, kao u slučaju numeričkog eksperimenta. Monte Karlo simulacije transporta protona kroz tanke slojeve SiO2, AlN, Al2O3 i polikarbonata su pokazali da su navedeni slojevi imuni na prolazak protona sa energijama većim od ∼10 MeV. Nejonizujući gubici energije ovih visokoenergetskih protona su mali i oni prolaze kroz slojeve bez mnogo atomskog rasejavanja. U donjem delu istraženog opsega protonske energije (od 10 keV do 1 MeV), treba očekivati značajne gubitke jonizacije. Jonizacija i oštećenja uzrokovana pomeranjima usled prolaska protona mogu uticati na svojstva pomenutih izolatora i ugroziti njihovu pouzdanost u složenim sklopovima i uređajima. Tačkasti defekti, od kojih su neki donori nosača naelektrisanja, nastaju u ozračenim izolatorima kao rezultat pomeranja (dislokacije) atoma. Visoko reaktivni slobodni radikali koji se mogu pojaviti u ozračenom leksanu izazivaju cepanje lanca i/ili umrežavanje, što utiče na izolaciona svojstva polikarbonatnih slojeva.The doctoral dissertation discusses the effect of nuclear and electromagnetic radiation on thin insulating layers that are crucial in the separation of electronic components and structures in multilayer densely packed integrated circuits. The thickness reducing of the active and passive layers of integrated circuits makes them very sensitive to the effects of ionizing radiation and the occurrence of overvoltages of atmospheric and commutation origin. In parallel with the production of such electronic circuits, the development of technology has led to an increase in nuclear and electromagnetic environmental contamination. The simultaneous emergence of thin multilayer electronic circuits and nuclear contamination has resulted in synergies that have limited further minimization of electronic components and assemblies by setting a clear limit to which it can go. With regard to the effects of nuclear radiation and overvoltage, the effect that can lead to the breakthrough of thin insulating structures is particularly undesirable. Such an effect leads to a short circuit of electronic assemblies and components, which completely destroys the multilayer densely packed integrated circuit as well as the overall system in which the circuit is installed. A particularly unfavorable situation is when the action of ion radiation creates greater damage in the insulating layer, which then breakthrough even overvoltages of submilivolt intensity, ie. when there is a synergy between the mechanically destructive effect of ion radiation and the electrical destruction of rapid surges. In order to obtain a picture of the reliability of commercial electrical multilayer integrated electronic components in the field of ion radiation, in this doctoral dissertation we decided on a numerical experiment using the Monte Carlo method. In doing so, the optimal random number generator was chosen and a model of the test multilayer integrated circuit suitable for the application of the set numerical experiment was made. A real experiment, which is easier to perform, is avoided because it gives integral radiation compatibility, and not differential, as in the case of a numerical experiment. Monte Carlo simulations of proton transport through thin layers of SiO2, AlN, Al2O3 and polycarbonate have shown that the investigated layers are immune to the passage of protons with energies higher than ∼10 MeV. Nonionizing energy loss of these high energy protons is low, and they traverse the layers without much atomic displacement. In the lower part of the investigated proton energy range (from 10 keV to 1 MeV), however, substantial ionization losses are to be expected. Ionization and displacement damage produced by protons could influence the properties of these insulators and compromise their reliability within complex structures and devices. Point defects, some of which are charge-carrier donors, arise in irradiated insulators as a result of atomic displacements. Highly reactive free radicals that can appear in irradiated lexan cause chain scission and/or cross-linking, which then affects the insulating properties of polycarbonate layers

Possibility of achieving an acceptable response rate of gas-filled surge arresters by substitution of alpha radiation sources by selection of electrode material and the electrode surface topography

The possibility of substituting the usage of a radioactive a-source to improve the characteristics of the gas surge arrester is considered in this paper. The solution to this problem is sought in the engineering of the characteristics by applying different electrode materials and varying electrode surface topography. Materials that differ in the output work value were examined. The electrode surface topographies were either polished, or with engraved regular spikes, or with polished cavities. The paper is mostly experimental in nature. The experiments were performed under well-controlled laboratory conditions. The measurement uncertainty of the experimental procedure was satisfactory. Experimental results were processed by sophisticated statistical methods of low statistical unreliability. The obtained results show that it is possible to avoid the installation of a radioactive source in the gas surge arresters and how it should be done. In this way, a possible contamination of the natural environment with extremely dangerous alpha - radioactive sources would be avoided