As the limitations of Moore’s Law become evident, there has been growing interest in advanced packaging technologies. Among various 3D packaging techniques, Cu-SiO2 hybrid bonding has gained attention in heterogeneous devices. However, certain issues, such as its high-temperature processing conditions and copper oxidation, can affect electrical properties and mechanical reliability. Therefore, we studied depositing only a heterometal on top of the Cu in Cu-SiO2 composite substrates to prevent copper surface oxidation and to lower bonding process temperature. The heterometal needs to be deposited as an ultra-thin layer of less than 10 nm, for copper diffusion. We established the process conditions for depositing a Co film using a Co(EtCp)2 precursor and utilizing plasma-enhanced atomic layer deposition (PEALD), which allows for precise atomic level thickness control. In addition, we attempted to use a growth inhibitor by growing a self-assembled monolayer (SAM) material, octadecyltrichlorosilane (ODTS), on a SiO2 substrate to selectively suppress the growth of Co film. We compared the growth behavior of the Co film under various PEALD process conditions and examined their selectivity based on the ODTS growth time.

The semiconductor industry faces physical limitations due to its top-down manufacturing processes. High cost of EUV equipment, time loss during tens or hundreds of photolithography steps, overlay, etch process errors, and contamination issues owing to photolithography still exist and may become more serious with the miniaturization of semiconductor devices. Therefore, a bottom-up approach is required to overcome these issues. The key technology that enables bottom-up semiconductor manufacturing is area-selective atomic layer deposition (ASALD). Here, various ASALD processes for elemental metals, such as Co, Cu, Ir, Ni, Pt, and Ru, are reviewed. Surface treatments using chemical species, such as self-assembled monolayers and small-molecule inhibitors, to control the hydrophilicity of the surface have been introduced. Finally, we discuss the future applications of metal ASALD processes.

In this study, we have investigated a selective emitter using a UV laser on BBr3 diffusion doping layer. The selective emitter has two regions of high and low doping concentration alternatively and this structure can remove the disadvantages of homogeneous emitter doping. The selective emitters were fabricated by using UV laser of 355 nm on the homogeneous emitters which were formed on n-type Si by BBr3 diffusion in the furnace and the heavy boron doping regions were formed on the laser regions. In the optimized laser doping process, we are able to achieve a highly concentrated emitter with a surface resistance of up to 43 Ω/□ from 105 ± 6 Ω/□ borosilicate glass (BSG) layer on Si. In order to compare the characteristics and confirm the passivation effect, the annealing is performed after Al2O3 deposition using an ALD. After the annealing, the selective emitter shows a better effect than the high concentration doped emitter and a level equivalent to that of the low concentration doped emitter.

Silicon heterojunction solar cells can achieve high conversion efficiency with a simple structure. In this study, we investigate the passivation characteristics of VOx thin films as a hole-selective contact layer using ALD (atomic layer deposition). Passivation characteristics improve with iVoc (implied open-circuit voltage) of 662 mV and minority carrier lifetime of 73.9 μs after post-deposition annealing (PDA) at 100 oC. The improved values are mainly attributed to a decrease in carbon during the VOx thin film process after PDA. However, once it is annealed at temperatures above 250 oC the properties are rapidly degraded. X-ray photoelectron spectroscopy is used to analyze the chemical states of the VOx thin film. As the annealing temperature increases, it shows more formation of SiOx at the interface increases. The ratio of V5+ to V4+, which is the oxidation states of vanadium oxide thin films, are 6:4 for both as-deposition and annealing at 100 oC, and 5:5 for annealing at 300 oC. The lower the carbon content of the ALD VOx film and the higher the V5+ ratio, the better the passivation characteristics.

Hole carrier selective MoOx film is obtained by atomic layer deposition(ALD) using molybdenum hexacarbonyl[Mo(CO)6] as precursor and ozone(O3) oxidant. The growth rate is about 0.036 nm/cycle at 200 g/Nm of ozone concentration and the thickness of interfacial oxide is about 2 nm. The measured band gap and work function of the MoOx film grown by ALD are 3.25 eV and 8 eV, respectively. X-ray photoelectron spectroscopy(XPS) result shows that the Mo6+ state is dominant in the MoOx thin film. In the case of ALD-MoOx grown on Si wafer, the ozone concentration does not affect the passivation performance in the as-deposited state. But, the implied open-circuit voltage increases from 576 oC to 620 oC at 250 g/Nm after post-deposition annealing at 350 oC in a forming gas ambient. Instead of using a p-type amorphous silicon layer, high work function MoOx films as hole selective contact are applied for heterojunction silicon solar cells and the best efficiency yet recorded (21 %) is obtained.

본 연구에서는 PAN과 폴리설폰의 두 지지체와 PEBAX 1657, 2533 두 선택층을 형성하였고, 지지체의 투과저항으로 인한 복합 막의 기체 투과도와 선택도의 차이를 확인하였다. 투과선택도를 향상시키기 위하여 PEG를 첨가하여 20에서 50 wt% 범위에서 농도를 달리하여 막을 제조한 후 CO2, N2 기체 투과성능을 측정하였다. 투과 성능이 가장 우수한 복합막의 물성 평가로써, PEBAX 복합평막의 미세구조를 관찰하였고, PEG 함량의 증가로 인한 Polyether 유리전이온도의 변화를 확인하였다. PEG 첨가제에 의한 PEBAX 복합평막은 에틸렌옥사이드 그룹으로 이루어진 PEG가 이산화탄소에 친화성을 가지고 있어서, PEG가 증가함에 따라 이산화탄소의 투과도를 향상시킬 수 있었다.

Simple and high efficiency green phosphorescent devices using an intermixed double host of 4, 4', 4"-tris(N-carbazolyl) triphenylamine [TCTA], 1, 3, 5-tris (N-phenylbenzimiazole-2-yl) benzene [TPBI], phosphorescent dye of tris(2-phenylpyridine)iridium(III) [Ir(ppy)3], and selective doping in the TPBI region were fabricated, and their electro luminescent characteristics were evaluated. In the device fabrication, layers of 70Å-TCTA/90Å-TCTA[0.5TPBI0.5/90Å-TPBI doped with Ir(ppy)3 of 8% and an undoped layer of 50Å-TPBI were successively deposited to form an emission region, and SFC137 [proprietary electron transporting material] with three different thicknesses of 300Å, 500Å, and 700Å were used as an electron transport layer. The device with 500Å-SFC137 showed the luminance of 48,300 cd/m2 at an applied voltage of 10 V, and a maximum current efficiency of 57 cd/A under a luminance of 230 cd/m2. The peak wavelength in the electroluminescent spectral and color coordinates on the Commission Internationale de I'Eclairage [CIE] chart were 512 nm and (0.31, 0.62), respectively.