The present invention provides a process for the
production of a semiconductor device comprising a semiconductor
element provided on a printed circuit board with a plurality of
connecting electrode portions provided interposed therebetween,
the gap between said printed circuit board and said
semiconductor element being sealed with an underfill resin
layer. In accordance with the present invention, (1) the
underfill resin layer is formed by melting a lamellar solid
resin provided interposed between said printed circuit board
and said semiconductor element, and (2) the lamellar solid
resin provided interposed between said printed circuit board
and said semiconductor element is heated for a predetermined
period of time until the temperature of the solid resin layer
reaches a predetermined range where the two components are
connected to each other under pressure under the following
conditions (X) and (Y):
 (X) Supposing that the initial residual heat of reaction of
the solid resin before heating is 100% as determined by a
differential scanning calorimeter (DSC), the residual heat of
reaction thereof is not more than 70% of the initial residual
heat of reaction; and (Y) The temperature of the semiconductor element is
predetermined higher than that of the printed circuit board,
and the difference in temperature between them is not less than
50°C. In this manner, a production process which facilitates the
resin sealing of the gap between the semiconductor element and
the board and thus can inhibit warpage of the entire
semiconductor device and a semiconductor device having an
excellent reliability can be provided. In the present
invention, the use of a sheet-like underfill material which
gives an underfill resin layer having an elastic modulus in
tension at 25°C of from 300 to 15,000 MPa when hardened can
provide a semiconductor device which exerts an excellent effect
of relaxing the stress on the semiconductor element, printed
circuit board and connecting electrode portions and thus
exhibits a high reliability.

Manufacture of semiconductor device

Recently, there has been much research in the field of nanostructure technology. The objective of this article is to explore the basic physics, technology, and applications of ultrasmall structures and devices with dimensions in the sub-100-nm range. Nanostructure devices are now being fabricated in many laboratories to explore various effects, such as those created by downscaling existing devices, quantum effects in mesoscopic devices, tunneling effects in single electron transistors, and so on. In addition, new phenomena are being explored in an attempt to build switching devices with dimensions down to the molecular level. Today, the minimum size of semiconductor production devices is down to 45 nm or less. Miniaturization and performance improvements are allowing the electronics industry to shrink the future size of semiconductor devices. For the last three decades, technological advances in optical lithography have led the semiconductor industry. In the present day mass-production line, deep ultraviolet (DUV 193 nm) optics is used for critical dimensions approaching 90 nm. A further decrease in immersion lithography has pushed the production line into the 32-nm era. However, as wavelengths decrease, optical lithography begins to suffer from difficulties associated with shallow focus length and materials (including lenses, masks and resists) to do with dispersion relationships. Therefore, non-optical lithographic techniques such as electron-beam direct write (L. Pain et al., 2006), electron-beam projection (J. Yamamoto et al., 2000), ion-beam projection (Y. Lee et al., 1998), and soft X-ray extreme ultraviolet (EUV 13 nm) (S. Hector, 1998; C. W. Gwyn et al., 1998) are being increasingly focused in order to replace or “mix & match” with optical lithography. Electron beam direct write is the only technology that does not require masking. Electron beam lithography (EBL) is one of the versatile lithographic tools widely used for nanostructure fabrication. In EBL, the critical dimension of the exposure patterns is limited by electron scattering in both electron-beam resists and substrates. The demand for fine patterns calls for EBL systems with high acceleration voltages. These have the advantage of having smaller forward scattering angles in the resist and a wide secondary-electron spread in the Source: Lithography, Book edited by: Michael Wang, ISBN 978-953-307-064-3, pp. 656, February 2010, INTECH, Croatia, downloaded from SCIYO.COM

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High-energy Electron Beam Lithography for Nanoscale Fabrication

PURPOSE:To automatically correct a change in the divergence angle of an electron beam emitted from the electron gun and to permit proper exposure even with brightness being changed due to correcting operations or a change with the lapse of time by an apparatus wherein the divergence angle of the electron beam is detected, the amount of electron beam irradiated to the sample is measured and a deflecting speed of the electron beam is changed. CONSTITUTION:The divergence angle is measured by detecting the current density profile of a formed spot of an electron beam 12 irradiated onto a beam forming aperture 5 with a reflected electron detector 47. A bias controller 29 judges whether correction is needed or not based on two data from a second comparator 28 and a processing circuit 30, and calculates a change width of bias resistance and the direction thereof to apply thus calculated results to a bias driving circuit 37. With this, the angular profile correction process to vary the bias resistance is completed. The amount of electron beam is measured by a Faraday cup 44 disposed on a stage 46. The output of the Faraday cup is amplified by a current/voltage conversion amplifier 48, while reference frequencies are applied to a multiplier 17 from a reference frequence register group 18. The deflection frequency with which the pattern is divided into rectangular froms for exposure is properly selected, so that the actual exposure amount becomes always constant. The deflection value is applied to a deflecting coil 10 via a deflection amplifier 23 to vary a speed of electron beam.

Electron beam exposure apparatus

Photolithography is a patterning process that uses light to transfer a pattern from a mask to a photosensitive polymer layer. The resulting pattern can either be etched into the underlying surface or used to define the patterning of a layer deposited onto the masked surface. This is essentially a two-dimensional process that can be repeated numerous times to fabricate various structures and devices. A classic use of these techniques is the fabrication of transistors on a silicon substrate as practiced in the semiconductor industry. Development over a number of years has yielded optimization of processing conditions, equipment, and materials to achieve ever smaller sized features and an increased density of integration. In the effort to fabricate even smaller (submicron to nanometer) features, other fabrication methods have also been developed such as electron beam lithography, focused ion beam lithography, and nanoimprint lithography. This chapter presents an introduction and practical approach to lithography and micromachining techniques in the context of MEMS device fabrication. The topics that are discussed here include: UV lithography, grayscale lithography, e-beam lithography, X-ray lithography, direct-write lithographies and imprint lithographies. A detailed description including highlighted examples of each of these lithographic techniques is presented in this chapter. At the end of the chapter a compilation of hands-on case studies is presented to assist readers in implementing these techniques in their own laboratories and developing custom fabrication capabilities that fulfill their own unique requirements.

MEMS Lithography and Micromachining Techniques

PROBLEM TO BE SOLVED: To solve the following problem: in a press, in which a laminate block, after being cut by a cutting blade in order to cut out a prescribed part from the block constituted of laminated ceramic green sheets and to press the prescribed part, is pressed by an upper platen and a lower platen while the cutting blade is kept in this state, and the cutting blade is deformed outside by stress generated by pressing pressure, hindering the linearity of a cut surface. SOLUTION: A channel 33 for receiving the edge part 28 of the cutting blade 27 after cutting the laminate block 22 is formed in the lower platen 23, and the outside deformation of the cutting blade 27 is suppressed while the block 22 is pressed by the upper platen 26 and the lower platen 23. COPYRIGHT: (C)2005,JPO&NCIPI

Apparatus for pressing laminate block

PURPOSE: To seize the size of an electron beam by measuring the time which corresponds to the electric-current variation caused by a shift in the relative position between the electron beam and a shield. CONSTITUTION: Electron-beam checker 16 is placed where an electron beam strikes, and in this state, the one-dimensional deflection of the electron beam is done. The electron beam is deflected to pass through the slit of shield 18, so that when the diameter of the slit opening is supposed to be greater than that of the electron beam, the waveform of the electronic current passing though the opening will be shown in the figure. Time t 2 -t 1 or t 4 -t 3 is in proportion to the size of the electron beam. COPYRIGHT: (C)1979,JPO&Japio

Electron-beam lithography unit

PURPOSE:To facilitate easy maintenance and to improve reliability through enabling an on-line measurement, by measuring luminous distribution of injected light providing a photometer on a movable test piece stage in a reduced projection type device thereby judging brightness to obtain the optimum intensity. CONSTITUTION:An image on a reticle 3 is projected in reduced sized on a wafer 5 and exposed on a chip. The movement of test piece table 6 by the opening and closing of a shutter 2 and step-and-repeat is controlled by a computer 15 based on the conditions input to a control console 18. The luminous intensity distribution of injected light 7 is measured by a step-and-repeat dividing an exposed area 21 into small measuring points 22 around the light axis 23 using a photometer provided on the table 6. Measured value of each point is inputted to the computer 15 via an AD converter 17 to be judged whether or not it is within the allowance of luminous dispersion. When it is not under the optimum condition, the measurement is repeated until the optimum condition is obtained by adjusting the current of a light source or the shutter speed. This makes possible the exposure in the optimum condition without deteriorating a through-put.

Kazumitsu Nakamura

Papers

Electron-beam lithography unit

Projection type exposure device