IEEE Transactions on Semiconductor Manufacturing

Multichip module (MCM) technology is considered a strategic solution in electronics packaging because this approach offers significant advantages in electrical and thermal performance and reliability. However, manufacturing cost is a critical issue for mass production of high-performance MCM packages. To realize low-cost manufacturing technology, process modeling, optimization, and control techniq... View full abstract»

This paper presents and applies a methodology for determining the optimal scale, type, and timing of IC manufacturing capacity additions when demand is uncertain. Using the methodology, six different 200-mm fab designs are evaluated, including standard 10 K- and 20 K-wafer start per month (ws/mo) facilities, a 5 K-ws/mo “minifab,” and “sequentially deployable” or “exp... View full abstract»

At a factory which produces a wide variety of products such as ASIC's or microcomputers, it is necessary to detect any machine causing a bottleneck and return it to a high level of performance for fast and effective production. This paper introduces a workflow control system called “JUSTICE/MORAL” (just time process control system/method of optimum-buffer restriction and adjustment log... View full abstract»

A temperature compensation concept suitable for rapid thermal processing (RTP) with a nonuniform wafer temperature distribution is proposed in this work. Concentric Si rings with different diameters are placed on planar quartz or Si susceptors and are regarded as patterned susceptors for temperature compensation. We put monitor wafers on the patterned susceptor and see the effect of the patterned ... View full abstract»

This paper presents a covariance-based interpolating procedure for constructing response surfaces that pass through all the data points created by computer-based experiments. The justification for this approach is that simulation-based experiments, in general, do not suffer from random errors. The paper presents the method in the context of fitting response surfaces to TCAD results for VLSI proces... View full abstract»

An ultrasonic sensor has been developed to monitor photoresist processing in situ, during semiconductor manufacturing. Photoresist development, pre-exposure bake, and post-exposure bake were monitored for the Shipley 1800 series I-line resists, and the pre-exposure bake of Shipley APEX-E deep-uv (DUV) resist was monitored as well. Development monitoring was achieved by measuring thickness changes ... View full abstract»

In this paper, we address the problem of developing accurate neural network equipment models economically. To this end, we propose model modifier techniques in conjunction with physical-neural network models. Two model modifiers-difference method and source input method-are proposed and evaluated on a horizontal chemical vapor deposition reactor. The results show that the source input method outpe... View full abstract»

The tungsten-stacked via structure will be widely used in future generations of semiconductors to increase the density of aluminum wiring. One problem with this structure is that film separation is sometimes observed at the interface between the aluminum wiring and the oxide layer. This separation occurs only in the specific stacked via structure, and it carries a risk of a potential reliability o... View full abstract»

The reliable and complete filling of vias and trenches with an appropriate metal is an important process in the fabrication of microelectronic components. Due to its favorable electronic properties and its reliability, copper is a common choice for replacing aluminum as a metallization material. One metallization procedure of interest is the sputter reflow of copper. The sputter reflow process beg... View full abstract»

Ammonia and hydrogen peroxide mixtures (APM) are widely used for removing particles from substrate surfaces in semiconductor manufacturing. In the next-generation manufacturing, more precise control of the APM cleaning performance is required than what is available today. In this study, a new method for evaluating the APM cleaning performance, such as the etching rate, surface microroughness, and ... View full abstract»

Conventionally, people focus on defect reduction to improve yield rate. Little research has been done to deal with the problem of optimizing wafer exposure patterns. This paper develops a computer-based procedure to maximize the number of dies possibly produced from a wafer. A program has been developed and implemented in a 6-in wafer fabrication factory in Taiwan. The results validate the practic... View full abstract»

When a 0.35-μm CMOS technology was introduced into manufacturing, a small fraction of the tested devices exhibited symptoms of source/drain underlap, despite the fact that all other monitors were well within the design control limits. Additional measurements showed variable overlap on various monitor structures on the same chip. The specific formulation of an HF wet clean was shown to be respon... View full abstract»

Variation in channel length degrades circuit reliability and yield. A common way to compensate for this problem is to increase the mean channel length, which, unfortunately, degrades circuit performance for digital circuits. One source of channel length variation is lithography, during which the line width is influenced by local layout patterns. It is possible to compensate for this effect by resi... View full abstract»

Actinometry has been used as the basis of a successful sensor for controlling fluorine concentration in fluorocarbon plasmas commonly employed in etching. An analogous sensor would be useful for chlorine plasmas as well. One problem with actinometry in Cl2 plasmas is that excitation can occur by electron impact dissociation and by dissociative attachment, leading to potential ambiguity ... View full abstract»

A new environment-friendly wastewater treatment technology was developed for the treatment of mixed acid drainage containing fluorine. The ordinary wastewater system using “slaked lime” is ineffective at removing fluorine; besides, it cannot decompose “hard-type surfactants” in the wastewater, so the amount of generated sludge and the quality of treated wastewater are not a... View full abstract»