Seed-layer 공정을 이용한 Ba_0.66Sr_0.34TiO₃박막의 제조 및 전기적 특성 연구

최덕영,박철호,손영국 한국세라믹학회 2003 한국세라믹학회지 Vol.40 No.2

R.F. Magnetron Sputtering법을 이용하여 Pt/Ti/ $SiO_2$/Si기판 위에 seed-layers와 $Ba_{0.66}$S $r_{0.34}$Ti $O_3$박막을 제조하였다. 다양한 기판온도에 따른 BST 박막의 전기적인 특성(정전용량과 누설전류)과 seed-layer층이 BST 박막에 미치는 영향을 조사하였다. BST 박막은 seed-layer층을 삽입함으로써 박막의 결정성이 향상되었고, 박막의 기판온도(결정화온도)도 상당히 낮출 수 있었다. 순수한 BST에 비하여 seed-layer를 삽입한 BST는 높은 유전상수와 낮은 유전손실 및 낮은 누설전류를 가지는 우수한 전기적 특성을 나타내었다. BST 박막의 전기적 특성은 기판온도에 따라 영향을 받고, seed-layer에 의해 향상됨을 알 수 있었다. $Ba_{0.66}Sr_{0.34}TiO_3$ thin films and seed-layers were deposited on $Pt/Ti/SiO_2/Si$substrate by R.F. magnetron sputtering method. Effects of various substrate temperature conditions on electrical properties (such as capacitance and leakage current) of BST thin films were studied. The effect of seed-layer was also studied. When seed-layer was inserted between BST and Pt, the crystallization of the BST thin films was considerably improved and the processing temperature was lowered. Compared to the pure BST thin films, dielectric constant, dielectric loss, and leakage current of BST thin films deposited on the seed-layer were considerably improved. It could be revealed that electrical properties are influenced by the substrate temperatures of BST thin films and are enhanced by the seed-layer.

Self-seed layer를 이용하여 증착한 SBT박막의 특성

김형섭,황동현,윤지언,손영국,Kim, Hyung-Sub,Hwang, Dong-Hyun,Yoon, Ji-Un,Son, Young-Gook 한국진공학회 2007 Applied Science and Convergence Technology Vol.16 No.3

[ $Pt/SBT/Seed/Pt/Ti/SiO_2/Si$ ]의 구조로 $SBT(SrBi_2Ta_2O_9)$ 박막을 Self-seed layer를 사용하여 R.F. Magnetron sputter를 이용하여 증착을 하였다. Self-seed layer는 기판온도 RT(room temperature)와 $600^{\circ}C$에서 두께 30 nm으로 증착하였다. Self-seed layer의 결정화 온도를 알아보기 위해 열처리온도를 변화시켰고 이를 XRD를 통하여 결정화 유무를 확인하였다. Self-seed layer 위에 증착한 SBT를 XRD와 전기적 측정을 통해 특성을 관찰하였다. Thin films of $SBT(SrBi_2Ta_2O_9)$ having $Pt/SBT/Seed/Pt/Ti/SiO_2/Si$ structure were fabricated using self-seed layer method by R.F. Magnetron sputter. Self-seed layers were deposited at room temperature and $600^{\circ}C$, which had 30 nm thickness. To investigate crystallization of self-seed layer we characterized by XRD after various heat treatment. And we characterized the crystallinity and electrical properties of SBT on self-seed layer after various heat treatment.

Effect of Growth Temperature during the Atomic Layer Deposition of the SrTiO₃ Seed Layer on the Properties of RuO₂/SrTiO₃/Ru Capacitors for Dynamic Random Access Memory Applications

Kim, Sang Hyeon,Lee, Woongkyu,An, Cheol Hyun,Kwon, Dae Seon,Kim, Dong-Gun,Cha, Soon Hyung,Cho, Seong Tak,Hwang, Cheol Seong American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.48

<P>The atomic layer deposition process of SrTiO<SUB>3</SUB> (STO) films at 230 °C was studied with Sr(<SUP>i</SUP>Pr<SUB>3</SUB>Cp)<SUB>2</SUB> and Ti(CpMe<SUB>5</SUB>)(OMe)<SUB>3</SUB> (Pr, Cp, and Me are propyl, cyclopentadienyl, and methyl groups, respectively) on Ru substrates. The growth behavior and properties of STO films grown at 230 °C were compared with those deposited at 370 °C. With the limited over-reaction of the Sr precursor during the initial growth stage at a lower temperature, the cation composition was more controllable, and the surface morphology after crystallization annealing at 650 °C had more uniform grains with fewer defects. Here, the excess reaction of the Sr precursor means the chemical-vapor-deposition-like growth of the SrO component mediated through the thermal decomposition of the adsorbed Sr precursor molecules. It was by the reaction of the Sr precursor with the oxygen supplied from the partly oxidized Ru substrate. The second STO was grown at 370 °C (main layer) on the annealed first STO layer (crystallized seed layer) to lead to the in situ crystallization of the main layer. Due to the improved microstructure of STO films induced by the seed layer deposited at 230 °C, the bulk dielectric constant of 167 was obtained for the main layer, which was higher than the value of 101 where the seed layer was deposited at 370 °C, even though the crystallization annealing condition of the seed layer and the deposition condition of the main layer were consistent. The seed layer grown at 230 °C, however, had a lower dielectric constant of only ∼49, whereas the high-temperature seed layer had a dielectric constant of ∼106. Therefore, the low-temperature seed layer posed a severe limitation in acquiring an advanced capacitor property with the involvement of a low-dielectric interfacial layer.</P> [FIG OMISSION]</BR>

Control of the microstructure of SnS photovoltaic absorber using a seed layer and its impact on the solar cell performance

Kang, Jeong-yoon,Kwon, Soo-Min,Yang, So Hyun,Cha, Jung-Hwa,Bae, Jin A.,Jeon, Chan-Wook Elsevier 2017 Journal of alloys and compounds Vol.711 No.-

<P><B>Abstract</B></P> <P>SnS thin films were prepared by sulfurizing a sputtered metallic Sn precursor film deposited on a Mo-coated sodalime glass substrate. Some of the precursors were deposited on a thin e-beam evaporated SnS seed layer with a 100–300 nm thickness and the effects of the seed layer on the sulfurization reaction were investigated. The seed layer provided nucleation sites for SnS crystals during the sulfurization and promoted a (040) preferred orientation, whereas a strong (101) orientation was observed in the non-seeded SnS absorber films. In addition, with introduction of the seed layer, the columnar grains observed in the non-seeded SnS film were transformed to an equiaxed grain structure with many grain boundaries. The SnS thin films with (040) preferential orientation and equiaxed crystal structure contributed not only to improvement of solar cell performance parameters, but also to ensuring uniformity between samples. This is considered to be related to the three-dimensional arrangement of the interlayer existing in the SnS unit cell having a very long b axis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> SnS obtained by sulfurization of Sn deposited on SnS seed layer. </LI> <LI> Strong (040) preferred orientation in seeded SnS absorber layer. </LI> <LI> Equiaxed SnS grans in seeded SnS in contrast to columnar grain in non-seeded SnS. </LI> <LI> Superior solar cell performance of seeded SnS absorber. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Cu Seed Layer의 열처리에 따른 전해동도금 전착속도 개선

권병국,신동명,김형국,황윤회,Kwon, Byungkoog,Shin, Dong-Myeong,Kim, Hyung Kook,Hwang, Yoon-Hwae 한국재료학회 2014 한국재료학회지 Vol.24 No.4

A thin Cu seed layer for electroplating has been employed for decades in the miniaturization and integration of printed circuit board (PCB), however many problems are still caused by the thin Cu seed layer, e.g., open circuit faults in PCB, dimple defects, low conductivity, and etc. Here, we studied the effect of heat treatment of the thin Cu seed layer on the deposition rate of electroplated Cu. We investigated the heat-treatment effect on the crystallite size, morphology, electrical properties, and electrodeposition thickness by X-ray diffraction (XRD), atomic force microscope (AFM), four point probe (FPP), and scanning electron microscope (SEM) measurements, respectively. The results showed that post heat treatment of the thin Cu seed layer could improve surface roughness as well as electrical conductivity. Moreover, the deposition rate of electroplated Cu was improved about 148% by heat treatment of the Cu seed layer, indicating that the enhanced electrical conductivity and surface roughness accelerated the formation of Cu nuclei during electroplating. We also confirmed that the electrodeposition rate in the via filling process was also accelerated by heat-treating the Cu seed layer.

Optimization of $p^+$ seeding layer for thin film silicon solar cell by liquid phase epitaxy

Lee, Eun-Joo,Lee, Soo-Hong The Korea Association of Crystal Growth 2005 한국결정성장학회지 Vol.15 No.6

Thickness optimization of heavily doped p-type seeding layer was studied to improve performance of thin film silicon solar cell. We used liquid phase epitaxy (LPE) to grow active layer of $25{\mu}m$ thickness on $p^+$ seeding layer. The cells with $p^+$ seeding layer of $10{\mu}m\;to\;50{\mu}m$ thickness were fabricated. The highest efficiency of a cell is 12.95%, with $V_{oc}=633mV,\;J_{sc}=26.5mA/cm^2$, FF = 77.15%. The $p^+$ seeding layer of the cell is $20{\mu}m$ thick. As thicker seeding layer than $20{\mu}m$, the performance of the cell was degraded. The results demonstrate that the part of the recombination current is due to the heavily doped seeding layer. Thickness of heavily doped p-type seeding layer was optimized to $20{\mu}m$. The performance of solar cell is expected to improve with the incorporation of light trapping as texturing and AR coating.

Cu seed layer 표면의 플라즈마 전처리가 Cu 전기도금 공정에 미치는 효과에 관한 연구

오준환,이성욱,이종무,O, Jun-Hwan,Lee, Seong-Uk,Lee, Jong-Mu 한국재료학회 2001 한국재료학회지 Vol.11 No.9

Electroplating is an attractive alternative deposition method for copper with the need for a conformal and conductive seed layer In addition, the Cu seed layer should be highly pure so as not to compromise the effective resistivity of the filled copper interconnect structure. This seed layer requires low electrical resistivity, low levels of impurities, smooth interface, good adhesion to the barrier metal and low thickness concurrent with coherence for ensuring void-free fill. The electrical conductivity of the surface plays an important role in formation of initial Cu nuclei, Cu nucleation is much easier on the substrate with higher electrical conductivities. It is also known that the nucleation processes of Cu are very sensitive to surface condition. In this study, copper seed layers deposited by magnetron sputtering onto a tantalum nitride barrier layer were used for electroplating copper in the forward pulsed mode. Prior to electroplating a copper film, the Cu seed layer was cleaned by plasma H$_2$ and $N_2$. In the plasma treatment exposure tome was varied from 1 to 20 min and plasma power from 20 to 140W. Effects of plasma pretreatment to Cu seed/Tantalum nitride (TaN)/borophosphosilicate glass (BPSG) samples on electroplating of copper (Cu) films were investigated.

종결정 코팅층이 다공성 ${\alpha}$-알루미나 지지체 표면에 성장되는 NaA 제올라이트 분리층의 미세구조에 미치는 영향

김민지,한문희,조철희,Kim, Min-Ji,Sharma, Pankaj,Han, Moon-Hee,Cho, Churl-Hee 한국막학회 2014 멤브레인 Vol.24 No.5

본 연구에서는 종결정 코팅층이 NaA 제올라이트 분리막 형성에 미치는 영향에 대하여 고찰하였다. NaA 제올라이트 분리막은 평균입경 100 nm 종결정을 다공성 ${\alpha}$-알루미나 표면에 진공여과 코팅하고 $100^{\circ}C$에서 24시간 수열처리하여 합성되었다. 이때 지지체 표면에 분포된 종결정 양을 조절한 후 형성된 NaA 제올라이트 분리층의 두께와 결정입 크기 등 미세구조에 미치는 영향에 대하여 고찰하였다. 종결정 코팅 양은 지지체를 통과한 종결정 수용액의 여과 양을 조절하여 제어하였다. 종결정을 단일층으로 코팅한 후 합성하였을 경우, 코팅 양이 증가함에 따라 분리층 단면에서의 두께와 균일도는 증가하였으며, 표면에서의 결정입 크기는 감소하면서 균일도는 증가하였다. 반면, 종결정을 다층으로 코팅한 후 합성하였을 경우, 균일한 분리층을 형성하였지만 단일층으로 코팅된 경우에 비하여 불균일하였으며 두꺼운 분리층이 형성되었다. 균일하고 초박형의 결함이 없는 제올라이트 분리층을 형성하기 위해서는 종결정을 균일하고 단일층으로 코팅하여야 함을 알 수 있었다. 본 연구로부터 종결정의 코팅 상태가 이차성장에 의한 NaA 제올라이트 분리층의 미세구조를 결정하는 중요한 인자임을 확인할 수 있었다. NaA zeolite/${\alpha}$-alumina composite membranes were hydrothermally synthesized at $100^{\circ}C$ for 24 hr by using nanosize seed of 100 nm in diameter and an ${\alpha}$-alumina support of $0.1{\mu}m$ in pore diameter, and then effect of seed coating layer on the microstructure of NaA zeolite separation layer was systematically investigated. In cases when nanosize seed was coated with a monolayer, increment in seed coverage induced small grained and thick NaA zeolite separation layer. On the other hand, in case when nanosize seed was coated with a multilayer, much small grained and thick separation layer was formed. It was clear that an uniform monolayer seed coating is required to grow hydrothermally a thin and defect-free NaA zeolite separation layer. In the present study, it was clearly announced that seed coating layer is a key factor to determine the microstructure of NaA zeolite layer, secondary grown on a porous support.

Role of n-type seed-layers in microstructural evolution of intrinsic nanocrystalline silicon and solar cell performance

Lee, J.E.,Ahn, S.,Park, J.H.,Yoo, J.,Yoon, K.H.,Kim, D.,Cho, J.S. Elsevier 2013 CURRENT APPLIED PHYSICS Vol.13 No.7

Nanocrystalline silicon (nc-Si:H) thin-film n-i-p solar cells were constructed on flexible stainless steel substrates by plasma-enhanced chemical vapor deposition. Influence of the n-type seed-layer on the microstructural evolution of the subsequent intrinsic nc-Si:H absorbers and the resultant performance of nc-Si:H solar cells was investigated. The crystalline volume fraction of the seed-layer can be effectively controlled by varying the hydrogen (H<SUB>2</SUB>) to silane (SiH<SUB>4</SUB>) gas flow ratio. Defect-dense amorphous regions were observed at the initial growth stage of the i-layers deposited on low crystalline volume fraction (X<SUB>c</SUB><SUP>n</SUP>) n-type seed-layers. Increasing the X<SUB>c</SUB><SUP>n</SUP> reduced the amorphous region at the n/i interface of the i nc-Si:H layers, evidenced by Raman scattering and transmission electron microscopy (TEM) measurements. Elimination of the defect-rich amorphous region within the i-layer by depositing the nc-Si:H solar cells on highly crystalline seed-layer caused significant improvements in the short circuit current density (J<SUB>sc</SUB>) and fill factor (FF). This is mainly due to the enhancement of long-wavelength light response and extraction efficiency of photo-carrier charges. The nc-Si:H solar cells prepared on a highly crystalline seed-layer (X<SUB>c</SUB><SUP>n</SUP>=73%) exhibited a 65.6% higher conversion efficiency than those on the n-type amorphous layers (X<SUB>c</SUB><SUP>n</SUP>=0%).

종결정 코팅층이 다공성 α-알루미나 지지체 표면에 성장되는 NaA 제올라이트 분리층의 미세구조에 미치는 영향

김민지,Pankaj Sharma,한문희,조철희 한국막학회 2014 멤브레인 Vol.24 No.5

NaA zeolite/α-alumina composite membranes were hydrothermally synthesized at 100°C for 24 hr by using nanosize seed of 100 nm in diameter and an α-alumina support of 0.1 μm in pore diameter, and then effect of seed coating layer on the microstructure of NaA zeolite separation layer was systematically investigated. In cases when nanosize seed was coated with a monolayer, increment in seed coverage induced small grained and thick NaA zeolite separation layer. On the other hand, in case when nanosize seed was coated with a multilayer, much small grained and thick separation layer was formed. It was clear that an uniform monolayer seed coating is required to grow hydrothermally a thin and defect-free NaA zeolite separation layer. In the present study, it was clearly announced that seed coating layer is a key factor to determine the microstructure of NaA zeolite layer, secondary grown on a porous support. 본 연구에서는 종결정 코팅층이 NaA 제올라이트 분리막 형성에 미치는 영향에 대하여 고찰하였다. NaA 제올라이트 분리막은 평균입경 100 nm 종결정을 다공성 α-알루미나 표면에 진공여과 코팅하고 100°C에서 24시간 수열처리하여 합성되었다. 이때 지지체 표면에 분포된 종결정 양을 조절한 후 형성된 NaA 제올라이트 분리층의 두께와 결정입 크기 등 미세구조에 미치는 영향에 대하여 고찰하였다. 종결정 코팅 양은 지지체를 통과한 종결정 수용액의 여과 양을 조절하여 제어하였다. 종결정을 단일층으로 코팅한 후 합성하였을 경우, 코팅 양이 증가함에 따라 분리층 단면에서의 두께와 균일도는 증가하였으며, 표면에서의 결정입 크기는 감소하면서 균일도는 증가하였다. 반면, 종결정을 다층으로 코팅한 후 합성하였을 경우, 균일한 분리층을 형성하였지만 단일층으로 코팅된 경우에 비하여 불균일하였으며 두꺼운 분리층이 형성되었다. 균일하고 초박형의 결함이 없는 제올라이트 분리층을 형성하기 위해서는 종결정을 균일하고 단일층으로 코팅하여야 함을 알 수 있었다. 본 연구로부터 종결정의 코팅 상태가 이차성장에 의한 NaA 제올라이트 분리층의 미세구조를 결정하는 중요한 인자임을 확인할 수 있었다.