Papers by Keyword: CMP

Abstract: Chemical mechanical polishing (CMP) is often employed to obtain a super smooth work-surface of a silicon wafer. However, as a conventional CMP is a loose abrasive process, it is hard to achieve the high profile accuracy and lots of slurry must be supplied during CMP operations. As an alternate solution, a fixed abrasive CMP process can offer better geometrical accuracy and discharges less waste disposal. In this paper, in order to enhance the polishing efficiency and improve the work-surface quality, a novel ultrasonic assisted fixed abrasive CMP (UF-CMP) is proposed and the fundamental machining characteristics of the UF-CMP of a silicon wafer is investigated experimentally. The results show that with the ultrasonic assistance, the material removal rate (MRR) is increased, and the surface quality is improved.

Abstract: Based on statistics theory and contact theory, a material removal model for predicting polishing quality in chemical-mechanical polishing (CMP) of multi-material surface is developed. The contacts of pad-workpiece and pad-particle-workpiece are characterized by the elastic–plastic contact mechanism. The material removal is considered to be the sum of the contributions from two movement modes of particles. Within the model, linear material removal volume (LMRV) can be determined as a function of the interactions of workpiece, pad and slurry. The model also determines the relationship between LMRV and roughness. It is found that polishing pad and parameters of polishing conditions have significant effects on the polishing quality. The experimental results show that chemical reagents contribute quite differently to multi-material end-face planarization. The proposed model reveals insights into improvement of the polishing quality of multi-material surface such as fiber array end-face.

Abstract: Multi-core processor parallels two or more computing core in a single processor to enhance computational capability. Plenty of former researches are focused on CMP (Chip multi-processor), the most typical structure of multi-core processor. Thus deign of cache coherence, in particular, is one of the primary problems beyond other researches about CMP. In this paper, cache coherence protocol of CMP is fully presented, along with its advantages and disadvantages. Finally, some edging issues of cache coherence protocols are addressed in this paper.

Abstract: In the recent years, the design and analysis of the security of e-commerce protocol has become a hot scheme. The confidentiality and fairness are important properties to measure the security of the e-commerce. It's also the important prerequisite of the successful protocol. Confidentiality and fairness are the basic properties of the secure e-commerce protocol. But the certified e-mail protocol as one of the e-commerce protocol can't satisfy these properties. This paper points out some drawbacks of teh CMP protocol, and analyses the protocol and makes improvements. The improved CMP protocol satisfies the confidentiality and fairness.

Abstract: To enhance polishing quality, polishing efficiency and improve the backward state based on single-process way for function ceramics in CMP, a new optimization method of process parameters based on multi-process and multi-evaluation theory is put forward. Firstly, based on experimental data obtained from orthogonal experiment, the optimal combinations of process parameters are got separately in term of surface roughness and material removal rate, which is optimized by Taguchi method in each process. Secondly, combining analysis of evaluation index weight ratio with analysis of variance, the final optimal combination of process parameters is received under the integrated evaluation of surface roughness and material removal rate. Finally, the contrast verification results show that the proposed optimization method is effective.

Abstract: With the advent of the information age, the theory of network-centric operations come into beings. Network and network devices constitute the core of the C3I system which is the cornerstone of the network-centric operations. However, it is difficult to maintenance and support the C3I network devices for the reason of its specific features, such as its all kinds of models, wide geographical distribution, complex structure, highly reliability requirements and so on [. we propose a network device monitoring method to improve network equipment running reliability, real-time fault detection and save the utilization of network resources based on the existing method.

Abstract: Long fiber component of poplar CMP is modified by ozone to improve the paper physical performance in this paper. The condition of modification is studied by the orthogonal test method. The results show that the optimum conditions are: 2.5% ozone, pH 4,consistency 0.5%. The softness, length, swelling properties and hydrophilcity of long fibers are improved after modification. The crystallinity of fiber is improved and the lignin content is reduced. The better performance in tear index and tensile index was attained compared with unmodified CMP holo-pulp to some extent: tensile index increased from 35.8N·m·g^-1 to 44.6N·m·g^-1, tear index increased from 4.58 mN·m²·g^-1 to 8.16 mN·m²·g^-1, brightness had a slightly increase.

Abstract: The properties of abrasives have great influences on the surface qualities of glass substrate, hard disk, etc^[1], during the chemical mechanical planarization (CMP) process. α-Al₂O₃ particles, as one of the most widely used abrasives in CMP slurries, often cause great surface defects because of its high hardness and unfeasible control of agglomeration during the synthesizing process ^[2,3]. In this paper, spherical nanocomposite alumina powders with particle sizes of 10-50 nm were prepared, via a homogeneous precipitation method. The structures and surface morphologies of the alumina nanopowders were characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM) and atomic force microscope (AFM). The results showed that the nanopowders composed of both alpha and theta phase alumina, which had a small particle size and narrow size distributions. The CMP investigations performed on glass substrate showed that the nanocomposite alumina abrasives exhibited a better surface planarization performance than the pure single alpha phase Al2O3 nanopowders, with lower surface roughnesses and less scratches after CMP process. The results indicated that the current processing for the synthesis of nanocomposite Al₂O₃ powders were of great potentials for practical applications of Al₂O₃ based abrasives.

Abstract: In this paper, the multi-hydroxyl polyamines researched by ourselves are used in the slurry of the copper wiring CMP of GLSI, which makes the slurry alkalization. It also has the using as a pH adjusting agent, complexion agent of copper ion, multi- metal chelating agents, aminating agent of acidic oxides, pH buffer, stainless steel corrosion inhibitor, the active agent and pro-oxidant. It improves the property of slurry and solves many different of acidity slurry. The alkalinity slurry contained the multi-hydroxyl polyamines is environmental, inexpensive and composition- simplified. Without the toxic BTA which is must be used in the international and has side effect, the slurry can achieve the high speed and high flat. In the same time the low pressure and the little abrasive can be realized, which provide the new material for the removal of TSV copper film.

Abstract: The chip-multiprocessor (CMP) have been main stream of current processors, and it integrates the multi-core into the chip so that it can make full use of the growing transistor resources; in the meantime the further development and utilization make the thread level parallelism become possible. In CMP structure Cache plays a more and more important role. So we introduce some new cache technology in this paper.