Microstructure Evolution of the Ir-inserted Ni Silicides with Additional Annealing

윤기정,송오성 대한금속·재료학회 2009 METALS AND MATERIALS International Vol.15 No.1

Thermally-evaporated 10 nm-Ni/1 nm-Ir/(poly)Si structures were fabricated in order to investigate the thermal stability of Ir-inserted nickel silicide after additional annealing. The silicide samples underwent rapid thermal annealing at 300℃ to 1200℃ for 40 s, followed by 30 min annealing at the given RTA temperatures. Silicides suitable for the salicide process were formed on the top of the single crystal and polycrystalline silicon substrates, mimicking actives and gates. The sheet resistance was measured using a four-point probe. High resolution x-ray diffraction and Auger depth profiling were used for phase and chemical composition analysis, respectively. Transmission electron microscope and scanning probe microscope were used to determine the cross-section structure and surface roughness. The silicide, which formed on single crystal silicon substrate with surface agglomeration after additional annealing, could defer the transformation of Ni(Ir)Si to Ni(Ir)Si2 and was stable at temperatures up to 1200℃. Moreover, the silicide thickness doubled. There were no outstanding changes in the silicide thickness on polycrystalline silicon. However, after additional annealing, the silicon-silicide mixing became serious and showed high resistance at temperatures >700℃. Auger depth profiling confirmed the increased thickness of the silicide layers after additional annealing without a change in composition. For a single crystal silicon substrate, the sheet resistance increased slightly due to the significant increases in surface roughness caused by surface agglomeration after additional annealing. Otherwise, there were almost no changes in surface roughness on the polycrystalline silicon substrate. The Ir-inserted nickel monosilicide was able to maintain a low resistance in a wide temperature range and is considered suitable for the nano-thick silicide process. Thermally-evaporated 10 nm-Ni/1 nm-Ir/(poly)Si structures were fabricated in order to investigate the thermal stability of Ir-inserted nickel silicide after additional annealing. The silicide samples underwent rapid thermal annealing at 300℃ to 1200℃ for 40 s, followed by 30 min annealing at the given RTA temperatures. Silicides suitable for the salicide process were formed on the top of the single crystal and polycrystalline silicon substrates, mimicking actives and gates. The sheet resistance was measured using a four-point probe. High resolution x-ray diffraction and Auger depth profiling were used for phase and chemical composition analysis, respectively. Transmission electron microscope and scanning probe microscope were used to determine the cross-section structure and surface roughness. The silicide, which formed on single crystal silicon substrate with surface agglomeration after additional annealing, could defer the transformation of Ni(Ir)Si to Ni(Ir)Si2 and was stable at temperatures up to 1200℃. Moreover, the silicide thickness doubled. There were no outstanding changes in the silicide thickness on polycrystalline silicon. However, after additional annealing, the silicon-silicide mixing became serious and showed high resistance at temperatures >700℃. Auger depth profiling confirmed the increased thickness of the silicide layers after additional annealing without a change in composition. For a single crystal silicon substrate, the sheet resistance increased slightly due to the significant increases in surface roughness caused by surface agglomeration after additional annealing. Otherwise, there were almost no changes in surface roughness on the polycrystalline silicon substrate. The Ir-inserted nickel monosilicide was able to maintain a low resistance in a wide temperature range and is considered suitable for the nano-thick silicide process.

Thermal-Annealing Effect of InP:Zn Implanted with Magnetic Impurities

김은규,김진석,손윤,고의관 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.5

Thermal-annealing effects of p-type InMnP:Zn samples were studied by using electrical measurements such as capacitance-voltage (C-V) and deep-level transient spectroscopy (DLTS). The annealing process was used to improve the properties of the InMnP and the annealing temperatures were 450, 550 and 600 ℃. From the results, we conrmed that the Mn-ion implantation process caused crystal defects in the InP and that a thermal annealing process at a proper temperature could recover the crystallinity and annihilate the defects. Five DLTS signals were found in the 600 ℃ annealed sample. In these, the origins of two signals were considered to be Mn-state and Mn-related clusters and their activation energies were 0.30 and 0.71 eV, respectively. Comparing the magnetic properties and the DLTS results, we found the good magnetic properties of the InMnP to be closely related to Mn-related levels and that these could be improved by thermal annealing. Thermal-annealing effects of p-type InMnP:Zn samples were studied by using electrical measurements such as capacitance-voltage (C-V) and deep-level transient spectroscopy (DLTS). The annealing process was used to improve the properties of the InMnP and the annealing temperatures were 450, 550 and 600 ℃. From the results, we conrmed that the Mn-ion implantation process caused crystal defects in the InP and that a thermal annealing process at a proper temperature could recover the crystallinity and annihilate the defects. Five DLTS signals were found in the 600 ℃ annealed sample. In these, the origins of two signals were considered to be Mn-state and Mn-related clusters and their activation energies were 0.30 and 0.71 eV, respectively. Comparing the magnetic properties and the DLTS results, we found the good magnetic properties of the InMnP to be closely related to Mn-related levels and that these could be improved by thermal annealing.

Effect of Annealing on the Conversion of ZnS to ZnO Nanoparticles Synthesized by the Sol-gel Method Using Zinc Acetate and Thiourea

Rizwan Wahab,S. G. Ansari,김영순,M. S. Dhage,서형기,송민우,신형식 대한금속·재료학회 2009 METALS AND MATERIALS International Vol.15 No.3

A systematic study is presented on the conversion of zinc sulfide to zinc oxide nanoparticles as a function of annealing temperature. Zinc acetate dihydrate (Zn(CH3COO)2.2H2O) and thiourea (NH2CSNH2) are used as precursors to synthesize ZnS and then ZnO. The aqueous solution of the precursor was refluxed at 90 °C for over 12 h. The synthesized complex was then annealed at 300 °C, 500 °C, 700 °C, and 900 °C in air for one hour. From elemental analyses, it was found that the as-synthesized powder is a mixture of ZnS and ZnO, which annealing later converts to the zinc oxide phase only. The morphological observations revealed spherical particles of various sizes (20 nm to 300 nm) while increasing the annealing temperatures. A drastic change in the vibration bands is noticed with annealing. Photoelectron peaks related to sulfur and carbon are observed for synthesized powder, whereas, these peaks disappeared when annealed at 500 °C. A systematic study is presented on the conversion of zinc sulfide to zinc oxide nanoparticles as a function of annealing temperature. Zinc acetate dihydrate (Zn(CH3COO)2.2H2O) and thiourea (NH2CSNH2) are used as precursors to synthesize ZnS and then ZnO. The aqueous solution of the precursor was refluxed at 90 °C for over 12 h. The synthesized complex was then annealed at 300 °C, 500 °C, 700 °C, and 900 °C in air for one hour. From elemental analyses, it was found that the as-synthesized powder is a mixture of ZnS and ZnO, which annealing later converts to the zinc oxide phase only. The morphological observations revealed spherical particles of various sizes (20 nm to 300 nm) while increasing the annealing temperatures. A drastic change in the vibration bands is noticed with annealing. Photoelectron peaks related to sulfur and carbon are observed for synthesized powder, whereas, these peaks disappeared when annealed at 500 °C.

In-Situ Pulse Laser Annealing 증착에 의한 광학박막의 표면 개선 효과

이세호,유연석,Lee, Se-Ho,Yu, Yeon-Serk 한국광학회 2009 한국광학회지 Vol.20 No.1

$MgF_2$, $SiO_2$ 및 ZnS 박막을 물리 증기 증착하는 동안 펄스 레이저(Nd-YAG, 제2고조파 532 nm)로 Annealing 하여 표면 거칠기 특성을 개선하였다. 펄스 반복율이 10 Hz, 펄스폭 5 ns, 파장 532 nm인 펄스레이저로 Annealing한 유리 기판에 증착된 $MgF_2$와 $SiO_2$ 시료들은 레이저 에너지가 $140\;mJ/cm^2$ 경우에 산란 총량 값이 최소가 되었지만, ZnS 박막의 경우에는 Annealing 레이저광 에너지가 $62\;mJ/cm^2$일 때 산란 총량이 최소값을 나타냈다. AFM을 사용하여 박막시료의 표면 거칠기에 대한 펄스 레이저 Annealing 효과를 측정 하였다. 그 결과는 TIS 측정치와 유사 하여 표면 거칠기는 Annealing 하기위해 조사된 레이저 에너지에 의존 하여 감소하였다. In-situ pulse laser (Nd-YAG, 2nd harmonics 532 nm) annealing used in physical vapor deposition of $MgF_2$, $SiO_2$ and ZnS thin films was shown to be effective in improving their surface roughness properties. Total integrated scattering (TIS) measurements of $MgF_2$ and $SiO_2$ samples deposited on glass substrates revealed that the laser irradiation of films at an energy of approximately $140\;mJ/cm^2$ at 532 nm with a repetition frequency of 10 Hz and pulse duration of 5 ns during the deposition resulted in total scatterings that were minimum. But in case of the ZnS samples, measurements revealed minimum total scattering at a laser energy of approximately $62\;mJ/cm^2$. Atomic Force Microscopy (AFM) has been used to evaluate the effect of pulse laser annealing on the surface roughness for thin film samples. The results were similar to the TIS measurements, indicating that surface roughness was decreased when the irradiated annealing pulse laser energy increased. But it also increased when the irradiated annealing pulse laser energy was over some limit that depended on the materials.

Ni-25at.%Al 금속간화합물의 연소합성반응에 미치는 사전 Annealing 처리의 영향

이한영(Han-Young Lee),모남규(Nam-Kyu Mo) 한국트라이볼로지학회 2021 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.37 No.2

The problem with intermetallics coating using the heat of molten casting is that the heat generated during combustion synthesis dissolves the coating and the substrate metal. This study investigates whether pre-annealing before synthesis can control the reaction heat, with the aim of Ni₃Al coating on the casting surface. Therefore, the effects of the annealing temperature and time on the combustion synthesis behavior of the powder compact of Ni-25at%Al after annealing were investigated. As results, the reaction heat when synthesized decreased as the annealing temperature was high and the annealing time was longer. This was attributed to the fact that Al was diffused to Ni particles during low temperature annealing and intermediate Ni-Al compounds were formed during high temperature annealing. After combustion synthesis, however, it was found that their microstructures were almost identical except for the amount of intermediate intermetallics. Furthermore, an annealing temperature above 450℃, at which intermediate compounds begin to form, is needed to prevent the dissolving problem during synthesizing. The intermetallics synthesized after annealing at higher temperature and prolonger annealing time showed a good wear resistance. This might be because much intermediate intermetallics of high hardness were remained in the microstructure.

Effect of Annealing Time on Electrical Performance of SiZnSnO Thin Film Transistor Fabricated by RF Magnetron Sputtering

고경민,이상렬 한국전기전자재료학회 2015 Transactions on Electrical and Electronic Material Vol.16 No.2

Thin film transistors (TFTs) with amorphous 2 wt% silicon-doped zinc tin oxide (a-2SZTO) channel layer werefabricated using an RF magnetron sputtering system, and the effect of post-annealing treatment time on thestructural and electrical properties of a-2SZTO systems was investigated. It is well known that Si can effectively reducethe generation of oxygen vacancies. However, it is interesting to note that prolonged annealing could have a badeffect on the roughness of a-2SZTO systems, since the roughness of a-2SZTO thin films increases in proportion to thethermal annealing treatment time. Thermal annealing can control the electrical characteristics of amorphous oxidesemiconductor (AOS) TFTs. It was observed herein that prolonged annealing treatment can cause bumpy roughness,which led to increase of the contact resistance between the electrode and channel. Thus, it was confirmed thatdeterioration of the electrical characteristics could occur due to prolonged annealing. The longer annealing time alsodecreased the field effect mobility. The a-2SZTO TFTs annealed at 500℃ for 2 hours displayed the mobility of 2.17 cm2/Vs. As the electrical characteristics of a-2SZTO annealed at a fixed temperature for long periods were deteriorated,careful optimization of the annealing conditions for a-2SZTO, in terms of time, should be carried out to achieve betterperformance.

차세대 전력 스위치용 1.5 ㎸급 GaN 쇼트키 장벽 다이오드

하민우(Min-Woo Ha) 대한전기학회 2012 전기학회논문지 Vol.61 No.11

The O₂ annealing technique has considerably suppressed the leakage current of GaN power devices, but this forms NiO at Ni-based Schottky contact with increasing on-resistance. The purpose of the present study was to fabricate 1.5 ㎸ GaN Schottky barrier diodes by improving O₂-annealing process and GaN buffer. The proposed O₂ annealing performed after alloying ohmic contacts in order to avoid NiO construction. The ohmic contact resistance (RC) was degraded from 0.43 to 3.42 Ω-㎜ after O₂ annealing at 800 ℃. We can decrease RC by lowering temperature of O₂ annealing. The isolation resistance of test structure which indicated the surface and buffer leakage current was significantly increased from 2.43×10? to 1.32×10<SUP>13</SUP> Ω due to O₂ annealing. The improvement of isolation resistance can be caused by formation of group-Ⅲ oxides on the surface. The leakage current of GaN Schottky barrier diode was also suppressed from 2.38×10<SUP>-5</SUP> to 1.68×10<SUP>-7</SUP> A/mm at ?100 V by O₂ annealing. The GaN Schottky barrier diodes achieved the high breakdown voltage of 700, 1400, and 1530 V at the anode-cathode distance of 5, 10, and 20 ㎛, respectively. The optimized O₂ annealing and 4 ㎛-thick C-doped GaN buffer obtained the high breakdown voltage at short drift length. The proposed O₂ annealing is suitable for next-generation GaN power switches due to the simple process and the low the leakage current.

Effect of Annealing Time on Electrical Performance of SiZnSnO Thin Film Transistor Fabricated by RF Magnetron Sputtering

Ko, Kyung Min,Lee, Sang Yeol The Korean Institute of Electrical and Electronic 2015 Transactions on Electrical and Electronic Material Vol.16 No.2

Thin film transistors (TFTs) with amorphous 2 wt% silicon-doped zinc tin oxide (a-2SZTO) channel layer were fabricated using an RF magnetron sputtering system, and the effect of post-annealing treatment time on the structural and electrical properties of a-2SZTO systems was investigated. It is well known that Si can effectively reduce the generation of oxygen vacancies. However, it is interesting to note that prolonged annealing could have a bad effect on the roughness of a-2SZTO systems, since the roughness of a-2SZTO thin films increases in proportion to the thermal annealing treatment time. Thermal annealing can control the electrical characteristics of amorphous oxide semiconductor (AOS) TFTs. It was observed herein that prolonged annealing treatment can cause bumpy roughness, which led to increase of the contact resistance between the electrode and channel. Thus, it was confirmed that deterioration of the electrical characteristics could occur due to prolonged annealing. The longer annealing time also decreased the field effect mobility. The a-2SZTO TFTs annealed at 500℃ for 2 hours displayed the mobility of 2.17 cm²/Vs. As the electrical characteristics of a-2SZTO annealed at a fixed temperature for long periods were deteriorated, careful optimization of the annealing conditions for a-2SZTO, in terms of time, should be carried out to achieve better performance.

Site-selective Photoluminescence Spectroscopy of Er-implanted Wurtzite GaN under Various Annealing Condition

Kim, Sangsig,Sung, Man Young,Hong, Jinki,Lee, Moon-Sook The Korean Institute of Electrical and Electronic 2000 Transactions on Electrical and Electronic Material Vol.1 No.1

The ~1540 nm $^4$ $I_{13}$ 2/ longrightarro $w^4$ $I_{15}$ 2/ emissions of E $r^{3+}$ in Er-implanted GaN annealed at temperatures in the 400 to 100$0^{\circ}C$ range were investigated to gain a better understanding of the formation and dissociation processes of the various E $r^{3+}$ sites and the recovery of damage caused by the implantation with increasing annealing temperature ( $T_{A}$).The monotonic increase in the intensity of the broad defect photoluminescence(PL) bands with incresing $T_{A}$ proves that these are stable radiative recombination centers introduced by the implantation and annealing process. Theser centers cannot be attributed to implantation-induced damage that is removed by post-implantation annealing. Selective wavelength pumpling of PL spectra at 6K reveals the existence of at least nine different E $r^{3+}$ sites in this Er-implanted semiconductor. Most pf these E $r^{3+}$ PL centers are attributed to complexed of Er atoms with defects and impurities which are thermally activated at different $T_{A}$. Only one of the nine observed E $r^{3+}$ PL centers can be pumped by direct 4f absorption and this indicates that it is highest concentration E $r^{3+}$ center and it represents most of the optically active E $r^{3+}$ in the implanted sample. The fact that this E $r^{3+}$ center cannot be strongly pumped by above-gap light or broad band below-gap absorption indicates that it is an isolated center, i.e not complexed with defects or impurities, The 4f-pumped P: spectrum appears at annealing temperatures as low as 40$0^{\circ}C$, and although its intensity increase monotonically with increasing $T_{A}$ the wavelengths and linewidths of its characteristic peaks asre unaltered. The observation of this high quality E $r_{3+}$PL spectrum at low annealing temperatures illustrates that the crystalline structure of GaN is not rendered amorphous by the ion implantation. The increase of the PL intensities of the various E $R_{3+}$sites with increasing $T_{A}$is due to the removal of competing nonradiative channels with annealing. with annealing.annealing.

Improved Transparent-Conducting Properties in N₂- and H₂-annealed GaZnO Thin Films Grown on Glass Substrates

이영민,김득영,이세준 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.60 No.1

The effects of N2- and H2-annealing on the transparent-conducting properties of Ga-doped ZnO (GaZnO) were examined. The as-grown GaZnO thin film, which was deposited on a soda-lime glass substrate by r.f. magnetron sputtering, exhibited moderate transparent-conducting properties: a resistivity of 100 -cm and an optical transmittance of 86%. After annealing in N2 or H2,the GaZnO samples showed great improvements in both the electrical and the optical properties. Particularly, in the H2-annealed sample, a dramatic decrease in the resistivity (7 × 10.4 -cm)with a considerable increase in the carrier concentration (4.22 × 1021 cm.3) was observed. This is attributed to both an increase in the number of Ga-O bonds and a reduction in the number of chemisorbed oxygen atoms though H2 annealing. The sample revealed an enhanced optical transmittance (91%), which comes from the Burstein-Moss effect. Namely, a blue-shift of the optical absorption edge, which results from the increased carrier concentration, was observed in the H2-annealed sample. The results suggest that hydrogen annealing can help improve the transparentconducting properties of GaZnO via a modification of the electrochemical bonding structures. The effects of N2- and H2-annealing on the transparent-conducting properties of Ga-doped ZnO (GaZnO) were examined. The as-grown GaZnO thin film, which was deposited on a soda-lime glass substrate by r.f. magnetron sputtering, exhibited moderate transparent-conducting properties: a resistivity of 100 -cm and an optical transmittance of 86%. After annealing in N2 or H2,the GaZnO samples showed great improvements in both the electrical and the optical properties. Particularly, in the H2-annealed sample, a dramatic decrease in the resistivity (7 × 10.4 -cm)with a considerable increase in the carrier concentration (4.22 × 1021 cm.3) was observed. This is attributed to both an increase in the number of Ga-O bonds and a reduction in the number of chemisorbed oxygen atoms though H2 annealing. The sample revealed an enhanced optical transmittance (91%), which comes from the Burstein-Moss effect. Namely, a blue-shift of the optical absorption edge, which results from the increased carrier concentration, was observed in the H2-annealed sample. The results suggest that hydrogen annealing can help improve the transparentconducting properties of GaZnO via a modification of the electrochemical bonding structures.