干冰微粒喷射清洗技术

简要介绍了随着工艺节点的缩小,传统RCA清洗方法在硅片清洗工艺中的局限性和弊端,进而提出了以CO2为介质的新型干冰微粒喷射清洗方法。从CO2的物理特性出发,论述了CO2流经喷枪后形成干冰微粒的机理,并简要分析了干冰微粒喷射技术对颗粒污染物和有机污染物的清洗机理。在此基础上,介绍了自主研发的一台基于干冰微粒喷射技术的半导体清洗设备,对该设备的结构和各部分的作用作了简要介绍,论述了使用该设备对硅片进行清洗的工艺流程。通过对比实验发现,采用压强为8 MPa、纯度为5N的CO2作为气源,喷嘴前压强设置为11 MPa,使用该设备可以达到很好的清洗效果。     

Transients in saturable reactors

Some interesting experimental results pertaining to magnetic-amplifier transients are reported, which seem to change present concepts on this subject.     

Transients in high-power modulators

The physical size involved in the design and construction of high-power modulators introduces high inductance and stray capacitance in the circuit. Analysis shows that under normal operation any inductance between the energy source and the RF device, together with stray capacitance, produces damped oscillations after the "turn-on" and "turn-off" of the RF generator beam. Unfortunately, the need for adequate protection of the RF generator and modulator requires the introduction of an additional inductor in the circuit to limit the rate of rise of fault current. Improper placement of this inductor can also produce detrimental oscillations under fault conditions. Proper design can minimize these unwanted transients. An analysis of the circuit and the results obtained in a high-power modulator are discussed.     

用热电器件实现的红外二氧化碳分析仪

文中介绍了一种采用钽酸锂热释电探测器作光电转换器件的红外二氧化碳浓度分析仪。描述了该仪器的基本原理与结构。该仪器基于朗伯－比尔定律，采用双光束结构、温度补偿、单片机数据处理及选用高性能的钽酸锂热释电探测器关键技术，能够对二氧化碳气体的浓度进行准确、有效的测量和分析。     

Transients in an ammonia-maser oscillator

Damped oscillations of the signal amplitude have been observed during the establishment time of strong oscillations in an ammonia-beam maser.