半导体工艺用高纯水中硅、硼的去除

本文主要研究了EDI(Electrodeionization)对高纯水中硅、硼的脱除方法.通过对电压、进水电导率(淡室、浓室)、流量(淡室、浓室、极室)、pH值等因素的研究,得出EDI最佳脱硅、硼条件.EDI进水SiO₂浓度为1000μg/L,最佳出水硅为2.66μg/L,为目前国内最好水平.EDI进水硼浓度为50μg/L,最佳出水中硼含量为＜1μg/L.满足了大规模集成电路用水中硅、硼的要求(对于兆位电路硅要求＜3μg/L,硼要求＜1μg/L).     

控制超大规模集成电路用水中的溶解氧和总有机碳浓度的研究

本文介绍了溶解氧(DO)以及总有机碳(TOC)对超大规模集成电路(ULSI)用水的污染,并列出了高纯水中TOC的浓度与栅氧化缺陷密度的关系数据.研究了影响水中DO的因素以及用各种方法降低TOC的比较,本文设计了用脱氧膜接触器,降低高纯水中的溶解氧.结合用双级反渗透(RO)及电脱盐(EDI) 再加上185nm紫外光照射高纯水,使高纯水中的溶解氧和TOC分别降至0.6μg/L和0.7μg/L,并用键能理论解释了185nm紫外降低TOC的机理.     

10%TMAH硅湿法腐蚀技术的研究

研究了浓度为10%的四甲基氢氧化铵(TMAH)溶液,在不同量的Si粉掺杂下,对铝膜及硅衬底的腐蚀及其pH值的变化。测试了在满足铝膜极低的腐蚀速率(<1nm/min)时,不同温度下该腐蚀液对硅(100)、(111)和(110)晶面及SiO2介质膜的腐蚀速率。还介绍了添加剂—过硫酸铵(APODS)和吡嗪的加入对腐蚀表面形貌及腐蚀速率的影响。研究结果表明,存在着一个临界的硅粉添加量,超过此量后铝膜的腐蚀速率急剧降低。90℃时,在10%TMAH溶液中加入1 5mol/L硅粉、3 0g/LAPODS和2g/L吡嗪可以实现铝膜不被腐蚀,同时硅(100)面约有1μm/min的腐蚀速率,腐蚀表面平整。腐蚀后的铝膜表面同硅铝丝键合良好,实现了腐蚀工艺同CMOS工艺的完全兼容。     

用EDI去除高纯水中痕量氨的新方法

本文研究了用电脱盐(Electrodeionization) EDI,去除高纯水中痕量氨(NH₃和NH₄⁺)的新方法.研究高纯水中弱离子化杂质氨的去除及其机理;研究了电流、进水电导率、进水流量和pH等对EDI去除水中氨(NH₃和NH₄⁺)的影响,进水氨浓度为208mg/L,经过一级EDI的处理,产品水中的总氨含量为0.072mg/L,对离子态铵也有很好去除效果,对进水中NH₄Cl浓度为20mg/L~100mg/L,产品水中铵浓度＜0.026mg/L.结果说明这方法是目前处理高纯水中痕量氨最好结果,远远低于太空用水＜0.5mg/L的要求.还研究了水中氨在EDI中被去除时的物种形态.     

毫米波掺碳基区AlGaAs/GaAs HBT

<正> 最近Ford微电子公司采用低压MOVPE技术以碳作为基区层掺杂剂制作了具有毫米波性能的HBT。采用重掺杂碳的基区层,既能降低基区电阻,又能维持高发射极注入效率所需的突变的受主分布。HBT所需外延层是用多片低压MOVPE系统生长的,碳掺杂源为四氯化碳,重掺杂基区的载流子浓度高达1×10~(20)cm~(-3),霍耳迁移率为65cm~2/V·s。器件用自对准技术制成,尺寸为1.5μm×8.5μm,所用工艺有:化学台面腐蚀、H_2~+离子注入隔     

富硅氧化硅微盘的制备研究

采用等离子体增强化学气相沉积(PECVD)及高温退火工艺制备了富硅氧化硅(SRSO)薄膜材料.喇曼光谱仪探测表明,该材料具有较高的光致发光(PL)效率,并在750 nm波长处达到发光峰值.采用电子束光刻(EBL)及电感耦合反应离子刻蚀(ICP)技术在Si衬底上制备了基于富硅氧化硅材料的光学微盘结构.为防止Si衬底的光吸收,在反应离子刻蚀(RIE)系统中研究出一种各向同性的刻蚀工艺,有效使微盘与Si衬底分离.扫描电镜(SEM)探测表明,该工艺具有良好的尺寸控制及高稳定性.利用该工艺,成功制备了直径为4μm的富硅氧化硅微盘器件.     

新书预告

北京有色金属研究总院(Grinm)、有研半导体材料股份有限公司(Gritek)张厥宗编著的《半导体材料硅单晶抛光片的加工技术》一书近期将由《化学工业出版社》出版。《半导体材料硅单晶抛光片的加工技术》在内容上采取由浅入深的方式,在介绍半导体硅及集成电路有关知识的同时,简单介绍半导体工业及国外、国内半导体材料硅(Si)单晶、抛光片技术的发展和动态外,结合能满足小于线宽0.130.10μm IC工艺用优质大直径硅(Si)单晶抛光片的加工技术进行全面、系统的概述。全书共分八章。第一章介绍半导体工业发展及动态和国外、国内硅(Si)单晶、抛光片…     

a-Si/μc-Si叠层电池中间层材料SiO_x:H制备研究

为提高a-Si/μc-Si叠层太阳电池的效率,采用射频等离子体增强化学气相沉积(RF-PECVD)技术,制备了系列n型掺磷硅氧(SiOx:H)薄膜作为中间层,研究了CO2/Si H4气体流量比、沉积功率和PH3掺杂浓度等工艺参数对材料光电特性的影响,获得了折射率、电导率和禁带宽度能够在较大范围内调控的SiOx:H薄膜。     

InGaN/AlGaN双异质结绿光发光二极管

报道了用 LP- MOVPE技术在蓝宝石 ( α- Al2 O3)衬底上生长出以双掺 Zn和 Si的 In Ga N为有源区的绿光 In Ga N/Al Ga N双异质结结构 ,并研制成功发射波长为 52 0— 540 nm的绿光LED.     

红外探测器材料Ⅱ

一、HgCdTe的外延与分子束外延生长 1.用MOVPE生长在(211)B CdTe/Si衬底上的HgCdTe膜层的特性(S.H.Suh等,韩国科技研究所)     

Wide-temperature-range operation of 1.3-/spl mu/m beam expander-integrated laser diodes grown by in-plane thickness control MOVPE using a silicon shadow mask

A new fabrication method of high-quality thickness-tapered semiconductor waveguides is proposed based on controlling in-plane thickness during MOVPE by using a comb-shaped silicon shadow mask. It was used to fabricate a 1.3-/spl mu/m-wavelength narrow-beam (less than 13/spl deg/) InGaAsP-InP laser diode, which achieved high-power (over 20 mW) operation up to 85.     

Laser diodes integrated with butt-jointed spotsize converterfabricated on 2-in wafer

Laser diodes integrated with spotsize converters by butt-joint technology combined with selective area metal organic vapor phase epitaxial (MOVPE) growth have been successfully fabricated. Satisfactory uniformity, reproducibility (>99%) and tolerance for low threshold current, a narrow emitted beam, and low optical coupling loss to fiber (<-2.4 dB) are obtained by using 2-in full wafer fabrication technology in the experimental fabrication. To investigate the tolerance in fabrication, the characteristic dependence on the variation of the wet etching time just before the butt-joint MOVPE growth and also on the mesa stripe width are investigated. A wide tolerance for these fabrication parameters is confirmed. The results indicate that the butt-joint technology is a useful and reliable process for realizing spotsize converters of the present type and also suggest that the technology is widely applicable to various photonic integrated circuits     

High speed non-selfaligned InP/InGaAs Npn heterojunction bipolar transistor grown by low pressure metal organic vapour phase epitaxy

Lattice matched GaInAs/InP Npn heterojunction bipolar transistors (HBTs) have been grown by lower pressure metal organic vapour phase epitaxy (MOVPE) and precessed with non-selfaligned fabrication techniques. The transistors exhibit a cutoff frequency of 60 GHz and maximum oscillation frequency of 32 GHz which are the highest values reported to date for GaInAs/InP HBTs grown by MOVPE.<>     

Fabrication of ultra-thin strained silicon on insulator

A bond and etch back technique for the fabrication of 13-nm-thick, strained silicon directly on insulator has been developed. The use of a double etch stop allows the transfer of a thin strained silicon layer with across-wafer thickness uniformity comparable to the as-grown epitaxial layers. Surface roughness of less than 1 nm was achieved. Raman analysis confirms strain remains in the thin silicon layers after the removal of the SiGe that induced the strain. Ultra-thin strained silicon-on-insulator (SSOI) substrates are promising for the fabrication of ultra-thin body and double-gate, strained Si metal-oxide semiconductor field-effect transistors (MOSFETs).     

Multi-layer microstructure fabrication by combining bulk silicon micromachining and UV-LIGA technology

A novel method for fabrication of multi-layer microstructures of microelectro-mechanical system (MEMS) devices is described. This technique, which combines bulk silicon micromachining technique and UV-LIGA technique can overcome some shape limitations of single technique on complex microstructures. To demonstrate this combination, the SU-8 microstructure fabricated in the etched silicon grooves is presented. In this fabrication process, a SU-8 removal method by fuming sulfuric acid was introduced and a novel type of plastics PETG was tried in microhot embossing process. The proposed fabrication process can be applied to fabricating a high-aspect-ratio microstructure for a large displacement actuator and precision sensors. Moreover, this combined process enables the fabrication of more complex structures, which cannot be fabricated by bulk micromachining or UV-LIGA alone.     

Embedded benzocyclobutene in silicon: An integrated fabrication process for electrical and thermal isolation in MEMS

This paper reports a novel fabrication process to develop planarized isolated islands of benzocyclobutene (BCB) polymer embedded in a silicon substrate. Embedded BCB in silicon (EBiS) can be used as an alternative to silicon dioxide in fabrication of electrostatic micromotors, microgenerators, and other microelectromechanical devices. EBiS takes advantage of the low dielectric constant and thermal conductivity of BCB polymers to develop electrical and thermal isolation integrated in silicon. The process involves conventional microfabrication techniques such as photolithography, deep reactive ion etching, and chemical mechanical planarization (CMP). We have characterized CMP of BCB polymers in detail since CMP is a key step in EBiS process. Atomic force microscopy (AFM) and elipsometry of blanket BCB films before and after CMP show that higher polishing down force pressure and speed lead to higher removal rate at the expense of higher surface roughness, non-uniformity, and scratch density. This is expected since BCB is a softer material compared to inorganic films such as silicon dioxide. We have observed that as the cure temperature of BCB increases beyond 200 °C, the CMP removal rate decreases drastically. The results from optical microscopy, scanning electron microscopy, and optical profilometry show excellent planarized surfaces on the EBiS islands. An average step height reduction of more than 95% was achieved after two BCB deposition and three CMP steps.     

GaAs microlens arrays grown by shadow masked MOVPE

This paper describes the fabrication of high quality GaAs microlenses and microlens arrays using shadow masked metalorganic vapor phase epitaxial (MOVPE) growth (SMMG). Microlenses with apertures as small as 30 μm were fabricated and focal lengths down to 40 μm were measured. The smaller lenses closely fit the theoretical behavior of ideal spherical lenses while larger lenses (focal length >80 μm) showed a more complex physical shape and could not be modeled as spherical. This deviation from a spherical shape is expected from simulation of SMMG. The full width at half maximum of the beam waist was <2 μm for all sizes of microlens indicating that these lenses are compatible with coupling to single mode fibers.     

All selective MOVPE grown BH-LDs fabricated by the novel self-alignment process

1.3 /spl mu/m-strained MQW BH LDs with a current blocking structure have been developed by selective MOVPE and a newly developed self-alignment process; we call these devices ASM (all selective MOVPE grown)-BH-LDs. The fabrication process, which completely eliminates semiconductor etching, is very promising to realize high-performance LDs with excellent uniformity and reproducibility. The light output power was remarkably improved by a factor of two, compared with previous selective MOVPE-LDs.     

All-selective MOVPE-grown 1.3-μm strained multi-quantum-wellburied-heterostructure laser diodes

Strained InGaAsP multi-quantum-well (MQW) double-channel planar-buried-hetero (DC-PBH) laser diodes (LDs) were fabricated by selective metalorganic-vapor-phase epitaxy (MOVPE). In the laser fabrication process, both the strained MQW active layer and current blocking structure were directly formed by selective MOVPE without any semiconductor etching process. The LDs are called all-selective MOVPE-grown BH LDs. The laser fabrication process can achieve both a precisely controlled gain waveguide structure and an excellent current blocking configuration, realizing the optimized DC-PBH structure. These aspects are essential to the high-performance and low-cost LD, which is strongly demanded for optical access network systems or fiber-to-the-home networks. This paper will show the excellent high-temperature characteristics for 1.3-μm Fabry-Perot LDs which have a record threshold current of 18 mA with a low-operation current of 56 mA for 10 mW, and 74 mA for 15 mW at 100°C with extremely high uniformity. Furthermore, reliable long-term operation at high temperature (85°C) and high-output power of 15 mW has been demonstrated for the first time