不同射频溅射功率下直接制备Ca2Si薄膜

磁控溅射系统在恒定Ar气压和Ar气流流量下,使用不同射频溅射功率在Si（100）衬底上分别沉积Ca薄膜;随后,800℃真空退火1 h.立方相的Ca2Si薄膜首次、单独、直接生长在Si（100）衬底上.实验结果指出,在多相共生的Ca-Si化合物中,沉积Ca薄膜时的射频溅射功率影响了立方相Ca2Si薄膜的质量;最优化的溅射功率是85 W.另外,退火温度为800℃时,有利于单一相Ca2Si的独立生长.并且,退火时间也是关键因素.     

射频溅射沉积不同厚度Ca膜退火直接形成Ca_2Si膜(英文)

使用射频磁控溅射系统在恒定溅射功率、Ar气压和Ar气流流量下,在Si(100)衬底上,分别沉积不同厚度的Ca膜。随后,800℃真空退火45分钟、1小时和1.5小时。半导体钙硅化物,即立方相的Ca2Si膜和简单正交相的Ca2Si膜首次、单独、直接生长在Si(100)衬底上。实验结果指明在多相共生的Ca-Si化合物中,Ca膜的沉积厚度、因溅射而生长的Ca-Si化合物的生长厚度决定了某一个单相的钙硅化物独立的生长。另外,退火温度为800℃时,有利于单相钙硅化物的独立生长。并且,退火时间也是关键因素。     

工作气压对制备立方氮化硼薄膜的影响

本文报道了工作气压对射频溅射法制备立方氮化硼(c-BN)薄膜影响的实验结果.c-BN薄膜沉积在p型Si(100)衬底上,溅射靶为六角氮化硼(h-BN),工作气体为Ar气和N2气混合而成,薄膜的成分由傅里叶变换红外吸收谱标识.结果表明,与射频功率、衬底温度和衬底负偏压一样,工作气压也是影响c-BN薄膜生长的重要参数.要得到一定立方相含量的氮化硼薄膜,必须要有合适的工作气压,否则,薄膜中不能形成立方相.在工作气压为5×10-3乇时,得到了立方相含量在90%以上的立方氮化硼薄膜.     

溅射功率对Ca2Si薄膜性质的影响

采用射频磁控溅射技术在Si（100）衬底上沉积了si-ca-si薄膜，并在高真空条件下对样品进行退火处理，直接生成立方相Ca2Si薄膜。研究了不同溅射功率对薄膜的晶体结构、表面（断面）形貌的影响，并对其光学性质进行了测试分析。结果表明：Ca2Si薄膜为立方结构且具有沿（111）向择优生长的特性，当溅射功率为120W时，Ca2Si薄膜变的均匀、致密，在400-800nm波长范围内，溅射功率对折射率n和吸收系数k的影响较小。     

氮化硼薄膜在退火相变中的应力研究

利用射频溅射系统在P型Si（100）衬底上制备氮化硼薄膜。对其进行600～1000℃的常压下N2保护退火。通过傅立叶变换红外谱（FTIR）分析，发现hBN-cBN-hBN的可逆相变。通过不同温度退火后立方相横光学振动模式峰位的移动，计算了氮化硼薄膜中残余应力的变化。发现沉积后退火很好地解决了高立方相氮化硼薄膜应力释放的问题，可提高立方氮化硼薄膜在硅衬底上的粘附性。并且探索性地讨论在退火过程中c-BN成核、生长与薄膜中应力变化的关系。     

低压MOCVD生长TiO2薄膜结构和电性能研究

采用低压MOCVD法沉积生长了TiO2薄膜，研究了Si衬底取向，退火温度，退火时间，退火气氛对其结构和电性能的影响，结果表明，500℃下沉积生长于Si(111)和Si(100)上的TiO2薄膜为锐钛矿相多晶膜，经过600℃以上退火处理后，均可转变为纯金红石相结构。其中，Si(111)上的TiO2薄膜更容易转变为金红石相结构，而Si(100)上的TiO2薄膜，需要更高的退火温度和更长的退火时间才能转变为金红石结构。结果还表明，退火气氛中氧分压的大小对TiO2薄膜的结构无明显的影响。     

Si(111)衬底上多层石墨烯薄膜的外延生长

利用固源分子束外延(SSMBE)技术, 在Si(111)衬底上沉积碳原子外延生长石墨烯薄膜, 通过反射式高能电子衍射(RHEED)、红外吸收谱(FTIR)、拉曼光谱(RAMAN)和X射线吸收精细结构谱(NEXAFS)等手段对不同衬底温度(400、600、700、800℃)生长的薄膜进行结构表征. RAMAN和NEXAFS结果表明: 在800℃下制备的薄膜具有石墨烯的特征, 而 400、600和700℃生长的样品为非晶或多晶碳薄膜. RHEED和FTIR结果表明, 沉积温度在600℃以下时C原子和衬底Si原子没有成键, 而衬底温度提升到700℃以上, 沉积的C原子会先和衬底Si原子反应形成SiC缓冲层, 且在800℃沉积时缓冲层质量较好. 因此在Si衬底上制备石墨烯薄膜需要较高的衬底温度和高质量的SiC缓冲层.     

Si衬底上RF磁控溅射MgO薄膜的研究

采用射频磁控溅射(rf magnetron sputte-ring)在Si(100)衬底上生长得到MgO薄膜。将在不同气压和Ar分压条件下得到的样品在氧气氛围下1000℃退火并进行X射线衍射(XRD)分析,结果表明,溅射总气压和O2分压影响MgO薄膜的择优取向,控制总气压和Ar分压可以控制MgO薄膜的晶格取向,Si衬底取向也对薄膜的择优取向产生影响。通过扫描电子显微镜(SEM)分析发现,MgO薄膜经过高温退火形成结晶并产生了表面裂纹。     

Sol-gel法制备Si基Bi_(3.15)Nd_(0.85)Ti_3O_(12)铁电薄膜

采用Sol-gel法分别在Si(100)和Si(111)衬底上制备Bi_(3.15)Nd_(0.85)Ti_3O_(12)(BNT)铁电薄膜。研究了衬底、退火温度、退火保温时间和薄膜厚度等因素对BNT铁电薄膜结晶和微观结构的影响。在500℃退火的BNT薄膜已经结晶形成层状钙钛矿相;升高退火温度(500～800℃)、延长保温时间(30～150min)、增加薄膜厚度(170～850nm),都有利于BNT薄膜晶粒长大,其中退火温度和薄膜厚度是影响晶粒长大的关键因素;每次涂覆的厚度大约是85nm。与Si(100)衬底相比,由于Si(111)与BNT薄膜具有更好的晶格匹配,因此BNT薄膜在Si(111)衬底上更容易结晶。     

脉冲激光沉积法制备β-FeSi_2半导体薄膜

采用脉冲激光沉积(PLD)法在p型Si(100)衬底上制备了β-FeSi2半导体薄膜,并在沉积系统中进行了800℃、3h的原位高温退火过程,最后采用X射线衍射仪、3D显微镜、原子力电子显微镜、荧光光谱仪分析了实验样品的晶体结构、表面形貌、元素组成、红外吸收和光致发光特性。分析实验结果发现,制备的单相β-FeSi2多晶半导体薄膜结晶质量良好,β-FeSi2在Si(100)衬底上沿(202/220)方向择优生长,且在常温下测得了β-FeSi2半导体薄膜的光致发光谱。     

A single phase semiconducting Ca-silicide film growth by sputtering conditions,annealing temperature and annealing time

Ca films were directly deposited on Si(100) substrates under the same sputtering power and Ar flux by Radio frequency (R.F.) magnetron sputtering system (MS) and were subsequently annealed at 800 °C for 90 min in a vacuum furnace. The structural and morphological features of the resultant films are tested by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive analysis of X-rays (EDAX). The cubic phase Ca₂Si film, the simple orthorhombic phase Ca₂Si film, and the tetragonal phase Ca₅Si₃ film are grown directly and individually on Si(100) substrates, respectively. The experimental results indicate that the selective growth of a single phase Ca-silicide from Ca–Si system of the existence of multiple silicide phases depends on sputtering conditions, annealing temperature, and annealing time. Besides, 800 °C is the adaptive annealing temperature for a single phase Ca-silicide film growth.     

Electrical Properties of Sputter-deposited ZrO2-based Pt/ZrO2/Si Capacitors

Pt/ZrO2/Si sandwich structures where ZrO2 is deposited by radio frequency （r.f.） magnetron sputtering using a Zr target in an atmosphere of O2/Ar gas mixture, were fabricated and the effects of the O2/Ar flow ratio in the reactive sputtering process, the annealing temperature, the ZrO2 film thickness on the structure, the surface roughness of ZrO2 films and the electric properties of Pt/ZrO2/Si metal-oxide-semiconductor （MOS） capacitors were investigated. The optimum process parameters of the Pt/ZrO2/Si capacitor based on reactively sputtered-ZrO2 determined in such a way as the capacitance is maximized and the leakage current, the oxide charge, and the interface trap density are minimized that is the O2/Ar flow ratio of 1.5, the annealing temperature of 800℃, and the film thickness of 10 nm. Also the conduction mechanism in the Pt/ZrO2/Si capacitor has been discussed.     

Photocatalytic Property of TiO2 Films Deposited by Pulsed DC Magnetron Sputtering

TiO2 thin films were prepared by DC magnetron sputtering with the oxygen flow rate higher than the threshold. The film deposited for 5 h was of anatase phase with a preferred orientation along the <220> direction, but the films deposited for 2 and 3 h were amorphous. The transmittance and photocatalytic activity of the TiO2 films increased constantly with increasing film thickness. When the annealing temperature was lower than 700℃, only anatase grew in the TiO2 film. TiO2 phase changed from anatase to rutile when the annealing temperature was above 800℃. The photocatalytic activity decreased with increasing annealing temperature.     

Mg2Si薄膜的磁控溅射制备及表征

采用直流磁控溅射的方法在Si(100)衬底上制备了Mg2Si外延半导体薄膜。通过XRD和FESEM对Mg2Si薄膜的晶体结构和表面形貌进行了表征,分析了溅射功率对Mg2Si薄膜制备的影响,得到了Mg2Si薄膜在不同溅射功率下的外延生长特性。结果表明,在Si(100)衬底上,Mg2Si薄膜具有(220)的择优生长特性,并且在50~80W的溅射功率范围内,随着溅射功率的增加,Mg2Si外延薄膜的衍射峰强度逐渐增强。     

Mg2Si／Si异质结的制备

采用射频磁控溅射和低真空退火方法制备Mg2Si／Si异质结,首先在n型Si（111）衬底上沉积Mg膜,经低真空退火形成Mg2Si／Si异质结,Mg膜厚度约为484nm,退火后形成的Mg2Si薄膜厚度约400nto,利用xRD和sEM分别研究了Mg2Si薄膜的晶体结构和表面形貌,霍尔效应结果表明,制备的Mg2Si薄膜呈现n型导电特性。     

Zr/Nb薄膜材料的制备及界面结构研究

通过直流磁控溅射法在单晶Si(100)基底上制备了Zr/Nb/Si薄膜材料。X射线衍射(XRD)研究表明Zr薄膜以多晶形式存在,而Nb薄膜则形成了(110)晶面择优生长。薄膜中Zr和Nb晶粒大小分别为14,6 nm。扫描电镜研究表明形成的薄膜表面平整光滑,没有微裂纹存在。扫描俄歇电子能谱及X射线光电子能谱的研究表明,Zr/Nb/Si薄膜样品具有清晰的界面结构。在薄膜表面形成了致密的氧化层物种,而在膜层内部少量氧则以吸附态形式存在。     

Preparation and characterization of highly <Emphasis Type="Italic">c</Emphasis>-axis textured MgO buffer layer grown on Si(100) substrate by RF magnetron sputtering for use as growth template of ferroelectric thin film

Highly c-axis textured MgO thin films were grown directly on Si(100) substrates without any buffer layer by RF magnetron sputtering for use as growth template of ferroelectric film. We fixed the target-to-substrate spacing of 40 mm and then changed the substrate temperature, deposition pressure, and RF power to study the effect of deposition parameters on the growth of c-axis textured MgO thin films. The as-grown films were post-annealed by the rapid thermal annealing (RTA) and furnace annealing to improve the film quality. The experimental results show that the optimum deposition parameters are substrate temperature of 350 °C, oxygen pressure of 15 mTorr and RF power of 75 W. The full width at half maximum intensity (FWHM) of MgO(200) peak obtained from the XRD measurement was 0.8°, and it was further reduced to 0.5° and 0.27° after annealing by RTA and furnace, respectively. Highly c-axis textured PZT and BaTiO₃ films could be obtained on this template. Hysteresis loops of the BaTiO₃ films deposited on MgO(100) single crystalline substrate and MgO(200)/Si(100) template were measured for comparison. The results show that MgO/Si templates thus obtained are suitable for the synthesis of perovskite ferroelectric thin films.     

直流磁控反应溅射制备IrO2薄膜

为研究氧化依（ＩｒＯ_２）对ＰＺＴ铁电薄膜疲劳性能的影响,利用直流（ＤＣ）磁控反应溅射（ｓｐｕｔｔｅｒｉｎｇ）工艺成功地在ＳｉＯ_２／Ｓｉ（１００）衬底上制得了高度取向的ＩｒＯ_２薄膜．并在其上制成ＰＺＴ铁电薄膜．讨论了溅射参数（溅射功率、 Ａｒ／Ｏ_２比、衬底温度）以及退火条件对氧化铱薄膜的结晶、取向和形态的影响．