ICP刻蚀机反应腔室气流仿真研究

感应耦合等离子体(ICP)刻蚀机反应腔室的气流分布是影响等离子体分布与刻蚀工艺均匀性的重要原因之一.使用商业软件CFD-ACE 中的连续流体与热传递模型,对反应腔室中气流分布进行了仿真研究,讨论了不同质量流量(50～250 cm3/min)入口条件下电极表面附近气压分布情况,同时讨论了不同腔室高度(H=0.08,0.12,0.14m)对气流分布均匀性的影响.研究发现电极表面附近气压分布呈现中心高边缘低的特征,并随入口质量流量的增加而升高;气流分布均匀性随腔室高度增加而有所提高,而同时平均密度却会下降.通过对比发现3D与2D模型仿真结果基本一致.     

金薄膜的反应离子刻蚀工艺研究

采用反应离子刻蚀（RIE）工艺对金薄膜进行了干法刻蚀研究,得到了刻蚀速率随两极间偏压、气体压强和气体成分等因素变化的规律。试验结果表明,刻蚀速率随偏压的增加而增大;当压强增加时,刻蚀速率先增加后减小;不同种类的气体对刻蚀速率影响较大;刻蚀时间与刻蚀厚度在一定范围内成正比。另外,找到了控制刻蚀过程均匀性和选择比的方法。     

压电型微悬臂梁制备中RIE刻蚀硅工艺的研究

介绍了一种压电型微悬臂梁的制作工艺流程,重点研究了其中硅的反应离子刻蚀(RIE)工艺,分析了工艺参数对刻蚀速率、均匀性和选择比的影响,提出通过适当调整气体流量、射频功率和工作气压,以加快刻蚀速率,改善均匀性,提高选择比。研究表明,在SF6流量为20 mL/min,射频功率为20 W,工作气压为8.00 Pa的工艺条件下,硅刻蚀速率可以提高到401 nm/min,75 mm(3 in.)基片范围内的均匀性为±3.85%,硅和光刻胶的刻蚀选择比达到7.80。为制备压电悬臂梁或其它含功能薄膜的微结构提供了良好的参考。     

反应离子刻蚀用于实现VLSI的多晶侧壁LDD MOSFET工艺优化研究

本文提出了采用多晶侧壁(PSSWS:Poly-Silicon Side-Wall Spacer)实现LDD MOSFET.研究了反应离子刻蚀(RIE)多晶硅的速率、各向异性性,对SiO_2、负胶的选择比,以及刻蚀的均匀性、过腐蚀度、负载效应等与刻蚀条件(包括气体、气体组分、流量、压力、射频功率、温度等)的关系.在此基础上,结合LDD MOSFET对侧壁宽度、可控性及重复性的要求,对反应离子刻蚀法实现PSSWS-LDD进行优化,获得了优化工艺条件.     

专利文摘

美国专利4492716 非晶半导体层的制造方法 Method of making noncrystalline semiconductor layer 将基片放入一个有气体入口和气体出口的反应室中,把至少包含一种半导体材料的气体和一种运载气体的混合气体引入反应室,反应室中的气体在这种状态下被排出。把电磁场加在混合气体上,使其在反应室中变成混合气体等离子体。利用混合气体等离子体在每个基片上沉积半导体材料。在这种情况下,使反应室中气氛压强保持低于1托以及使基片温度维持在低于半导体材料在基片上变成晶体时的温度,因此,半导体材料沉积在每个基片上变成非晶半导体。反应室在气体入口的一边设有气体离化区,在气体出口的一边为半导体沉     

纳米压印中残余胶刻蚀工艺研究

压印光刻在图形转移之后,需要去除残留在凹槽底部的胶。采用RIE工艺对紫外压印胶的刻蚀速率进行了研究。结果表明,随着气压或气体流量增大,刻蚀速率均会先增加,达到一定值后又开始下降;在刻蚀气体中加入SF_6后,会减少钻蚀,但刻蚀速率会有少许下降;而在刻蚀气体中加入少量SF_6且压强及流量较大时,各部分的刻蚀速率一致性较好。由此得到了一个优化后的刻蚀条件,反应气体:O_2+SF_6,气体流量分别为40 cm~3/min和5 cm~3/min,压强9.31 Pa,RF功率20 W,此时刻胶速率可稳定在0.8μm/min左右,且均匀性较好。     

聚酰亚胺微刻蚀加工工艺研究

研究了RIE刻蚀聚酰亚胺的刻蚀速率、刻蚀表面粗糙度与不同加工工艺参数(包括射频功率、腔室压力、刻蚀气体成分等)之间的相互关系。刻蚀速率与射频功率、腔室压力都呈线性关系,与气体成分的关系是低SF6含量时呈线性,高SF6含量时出现饱和。刻蚀面的粗糙度几乎不受腔室压力的影响,而射频功率高于300 W和低SF6含量时粗糙度会急剧上升。采用腔室压力40 Pa、功率275 W、O2流量80 cm3/min、SF6流量20 cm3/min,通过RIE刻蚀获得了深度为39.5μm的微腔结构,为形成柔性基底空腔以及上悬结构等提供了技术基础。此外,对柔性基底固定技术进行了研究,提出了一种有效固定聚酰亚胺膜的新工艺方法。     

PECVD SiC材料刻蚀技术

通过对PECVD SiC进行不同条件下的反应离子刻蚀(RIE)和电感耦合反应离子刻蚀(ICP)实验研究,提出了使用SF6和He的混合气体进行RIE刻蚀,并讨论了功率和压强分别对刻蚀速率的影响.进一步研究了SiC中H含量对于RIE刻蚀速率的影响,同时验证ICP刻蚀过程中负载效应的存在.     

PECVD SiC材料刻蚀技术

通过对PECVD SiC进行不同条件下的反应离子刻蚀(RIE)和电感耦合反应离子刻蚀(ICP)实验研究,提出了使用SF6和He的混合气体进行RIE刻蚀,并讨论了功率和压强分别对刻蚀速率的影响.进一步研究了SiC中H含量对于RIE刻蚀速率的影响,同时验证ICP刻蚀过程中负载效应的存在.     

掺镁铌酸锂晶体的ICP刻蚀性能

掺镁铌酸锂晶体(Mg:LiNbO3)是一种相对难刻蚀的晶体,Mg:LiNbO3的干法刻蚀速率和刻蚀形貌控制是铌酸锂光电子器件加工中的关键技术之一。采用牛津仪器公司的Plasmalab System 100以SF6/Ar为刻蚀气体,具体研究Mg:LiNbO3的刻蚀速率随着感应耦合等离子体(ICP)功率、反应离子刻蚀(RIE)功率、气室压强和气体流量配比等刻蚀参数的变化,同时研究发现SF6/(Ar+SF6)气体流量配比还会影响刻蚀表面的粗糙度。实验结果表明:在ICP功率为1000W,RIE功率为150W,标准状态(0℃,1个标准大气压)下气体总流量为52mL/min,压强为0.532Pa,SF6/(Ar+SF6)气体体积分数为0.077的条件下,刻蚀速率可达到152nm/min,刻蚀表面粗糙度为1.37nm,可获得刻蚀深度为2.5μm,侧壁角度为74.8°的表面平整脊形Mg:LiNbO3结构。     

The design and the fabrication of monolithically integrated GaInAsP MQW laser with butt-coupled waveguide

We optimized the etching process for butt coupling to improve the reproducibility and the uniformity of the process for the integrated GaInAsP multiquantum-well laser with a butt-coupled waveguide. Three different ways of etching process were tested, which are reactive ion etching (RIE), RIE followed by a small amount (50 nm thick) of selective wet etching, and RIE followed by an adequate amount (125 nm thick) of selective wet etching. RIE followed by an adequate amount of selective wet etching showed the superior properties to the common expectation on RIE only, giving the measured coupling efficiency 96/spl plusmn/1.7% versus 34/spl plusmn/8%. The high coupling efficiency and the very small variation across a quarter of a 2-in wafer demonstrate that RIE coupled with an adequate amount of selective wet etching can also replace the conventional process for butt coupling, RIE followed by HBr-based nonselective wet etching, to fabricate high-quality integrated photonic devices.     

红外加热吸附反应外延系统的温度均匀性研究

为指导全新的吸附反应外延技术ARE(Absorption Reaction Epitaxy, ARE)设备红外热源的设计,分析在真空腔室中红外管阵列的热流分布。通过对灯管阵列灯管数量、灯管间距、灯阵与硅片之间距离等设计参数。采用COMSOL Multiphysics软件进行仿真模拟,研究了以红外为热源的设备腔室及硅片温度场分布情况,实测硅片表面温度及均匀性与仿真基本吻合。结果表明在保证源在硅片表面良好扩散效果的同时,当灯管阵列灯管长度为200 mm,数量为11根,间距10 mm,距离硅片15 mm时硅片表面温度不均匀度达到0.683%,满足红外加热吸附反应外延工艺需求,可为ARE红外热源及腔室设计提供参考。     

A new gas circulation RIE

A new gas circulation RIE has been developed. It pumps the exhausted gas still containing usable process gas into the RIE process chamber to be reused. This new gas circulation RIE showed performances of etch rate, selectivity, etching profile, and uniformity in C₄ F₈/CO/Ar SiO₂ etching process comparable to those for the conventional process with 50% less C₄F₈ and 80% less CO and Ar of the original input gas flow rates. It also decreased PFC emission by two thirds less in CO₂ conversion. This new gas circulation RIE is effective for the suppression of the greenhouse effect and etching process cost     

Steady-state thermal uniformity and gas flow patterns in a rapidthermal processing chamber

The steady-state temperature distribution and gas flow patterns in a rapid thermal processing system are calculated numerically for various process conditions. The results are verified by comparison to experimental epitaxial growth rate data. The gas flow patterns and temperature distributions depend strongly on pressure and ambient composition. Steady-state uniformity is found to be described to first order by the radiant uniformity at the wafer surface and substrate heat flow considerations alone. For high-thermal-uniformity systems, however, convective cooling does play an important role, approximately equal to that of edge losses     

HgCdTe探测列阵干法技术的刻蚀形貌研究

首次报道了HgCdTe微台面焦平面探测列阵成形工艺的干法刻蚀技术有关刻蚀形貌的一些研究结果.从HgCdTe外延材料的特点出发,详细分析了其干法刻蚀适用的RIE(reactive ion etching)设备和刻蚀原理.采用高等离子体密度、低腔体工作压力、高均匀性和低刻蚀能量的ICP(inductively coupled plasma)增强型RIE技术,研究了不同的工艺气体配比、腔体工作压力、ICP源功率和RF源功率对HgCdTe材料刻蚀形貌的影响,并初步得到了一种稳定的、刻蚀表面清洁、光滑、图形轮廓良好、均匀性较好和刻蚀速率较高的干法刻蚀工艺.     

Coupled simulation of gas flow and heat transfer in an RTP-system with rotating wafer

In this study the concept of a lamp heated RTP-system with rotating wafer is considered. Using the fluid-flow-simulation software Phoenics-CVD, we investigated the cooling of the wafer by a process gas flow which is injected at room temperature into the hot process chamber through an inlet pipe in the side wall. In a full 3D-simulation of the gas flow and of the heat transfer in the gas and in the wafer the Navier–Stokes equations and the energy equation are solved. The radiative power consumption and the energy loss of the wafer have been modeled by the Stefan–Boltzmann law. Simulations without wafer rotation show a strong drop in the temperature distribution at the wafer near the inlet pipe. In contrast to this, simulations with rotation show an axisymmetric temperature distribution with a considerably smaller temperature gradient over the wafer. Comparisons with oxidation experiments showed good agreement with the simulation results.     

Reactive ion etching of gallium nitride films

Reactive ion etching (RIE) was performed on gallium nitride (GaN) films grown by electron cyclotron resonance (ECR) plasma assisted molecular beam epitaxy (MBE). Etching was carried out using trifluoromethane (CHF₃) and chloropentafluoroethane (C₂ClF₅) plasmas with Ar gas. A conventional rf plasma discharge RIE system without ECR or Ar ion gun was used. The effects of chamber pressure, plasma power, and gas flow rate on the etch rates were investigated. The etch rate increased linearly with the ratio of plasma power to chamber pressure. The etching rate varied between 60 and 500Å/min, with plasma power of 100 to 500W, chamber pressure of 60 to 300 mTorr, and gas flow rate of 20 to 50 seem. Single crystalline GaN films on sapphire showed a slightly lower etch rate than domain-structured GaN films on GaAs. The surface morphology quality after etching was examined by atomic force microscopy and scanning electron microscopy.     

进出口位置对槽道流体分配和换热的影响

针对平行小槽道的流量分配问题,设计了不同的进出口方式,并采用数值方法研究其对槽道散热器内流量分配和换热特性的影响。结果表明,进出口方式对槽道散热器内流量分配特性影响很大;提出流量和换热不均匀系数来评价进出口方式的影响,发现相同进出口方式下,流量不均匀系数随着流量的增大而增大;当槽道散热器流量相同时,顶部中间(UC)进出口形式的散热器内流量不均匀系数最小;当槽道面积一定时,流量不均匀系数随槽道个数增加而减小;流量一定时,槽道的表面温度不平均系数随加热功率的上升而增加;加热功率一定时,热阻随着流量的增加逐渐减小并趋于定值。     

凸点下金属层湿法刻蚀与凸点底切的控制

介绍了电镀凸点封装工艺流程和其中有关金属层湿化学刻蚀的问题.通过槽式批量和单片机刻蚀相应的UBM(凸点下金属层)的均匀度、刻蚀速率和凸点底切的对比,结果显示单片湿法刻蚀机刻蚀均匀度小于5%且片与片之间刻蚀速率差异小于2%,以及凸点底切小于2μm.槽式刻蚀均匀度较差,一般会大于20%,同时同一批次片与片之间刻蚀速率差异也较大,实验显示超过10%,且刻蚀后凸点底切较深.因此采用单片机进行UBM金属刻蚀可以较好的控制刻蚀过程和提高产品的良率.     

Mechanism of porous low-k film damage induced by plasma etching radicals

The etching damage on nano-clustering silica (NCS) film due to etching radicals was investigated using a method of radical treatments in RIE plasma. NCS coated-side of the wafer was turned downward and put at 0.65 mm above the wafer stage to investigate only the influence of radicals. Etching radicals, which comes from CF₄, diffuse into NCS film and reduce Si-CH₃ bonds and Si-CH₃ loss is proportional to the amount of diffused fluorine in NCS film. Several Si-CH₃ bonds are converted to Si-F bonds then. As a result, the low-k performance is degraded and especially the leakage current heavily increases. We proposed a method for estimating the degree of the sidewall damage due to etching radicals using blanket wafers. The degree of sidewall damage is proportional to the value of CR^−0.5, where C is the damage diffusion coefficient, which is derived from Si-CH₃ decrement ratio from a radical treatment result and R is the etching rate, which is derived from a RIE treatment result under the same plasma condition. The value of CR^−0.5 depends on the etching condition and must be decreased as much as possible in order to reduce the sidewall damage during RIE. For example, lower gas pressure, higher RF power, and higher CF₄/Ar gas flow ratio were desirable for the sidewall damage reduction.