JP2009071185A - Semiconductor device manufacturing method and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor device, which is capable of decreasing the influence of characteristic variations of a semiconductor chip, and to provide a semiconductor device. <P>SOLUTION: The method of manufacturing a semiconductor device includes: a process of preparing a semiconductor chip 10; a process of mounting the semiconductor chip 10 on a flexible package substrate 20; and a process of inspecting the performance of the semiconductor chip 10 mounted on the package substrate 20, and of bending the semiconductor chip 10 while bending the package substrate 20 in a direction in which the performance of the semiconductor chip 10 is enhanced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a semiconductor device manufacturing method and a semiconductor device.

  In recent years, there has been a remarkable increase in the speed of semiconductor devices. One of the major reasons for this increase in speed is the remarkable progress in miniaturization of semiconductor devices.

  However, the miniaturization of the semiconductor device complicates the semiconductor manufacturing process technology, and there is a problem that the MOSFET characteristics vary from one semiconductor chip to another. As a cause of the variation in the MOSFET characteristics, there is a semiconductor manufacturing process. For example, in the semiconductor manufacturing process, MOSFET characteristics vary due to impurity profile fluctuations, pattern shapes, dimensions, and the like.

  Therefore, semiconductors are manufactured in consideration of the variation in MOSFET characteristics for each semiconductor chip. However, as the semiconductor device is miniaturized, the allowable range of variation has become too large. In addition, in order to eliminate variations in MOSFET characteristics from one semiconductor chip to another, a stress film may be formed on a semiconductor chip with inferior performance to improve the performance of the semiconductor chip and to suppress variations in MOSFET characteristics of the semiconductor chip. However, the semiconductor manufacturing process becomes complicated.

As this type of related technology, an example of a semiconductor device and a method for manufacturing the semiconductor device is disclosed (for example, see Patent Document 1).
JP 2001-284402 A (page 11, FIG. 1)

  The present invention provides a method of manufacturing a semiconductor device and a semiconductor device that can reduce the influence of variations in characteristics of semiconductor chips.

  In order to achieve the above object, a method for manufacturing a semiconductor device of one embodiment of the present invention includes a step of preparing a semiconductor chip, a step of mounting the semiconductor chip on a bendable substrate, and an improvement in the performance of the semiconductor chip. A step of bending the substrate in a direction to be bent and bending the semiconductor chip.

  According to another aspect of the present invention, there is provided a semiconductor device including a semiconductor chip and a bendable substrate on which the semiconductor chip is mounted. The semiconductor chip and the substrate are improved in performance of the semiconductor chip. It is characterized by being curved.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a semiconductor device and a semiconductor device which can reduce the influence by the characteristic variation of a semiconductor chip can be provided.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view of a semiconductor device schematically showing the structure of the semiconductor device according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view of the semiconductor device schematically showing a state where the semiconductor device according to the first embodiment of the present invention is mounted on the package substrate. FIG. 3 is a cross-sectional view of a semiconductor device schematically showing a state where the semiconductor device according to the first embodiment of the present invention is mounted on a board.

  As shown in FIG. 1, the semiconductor device according to the first embodiment of the present invention includes a semiconductor chip 10 having a predetermined function, and a package substrate 20 that has the semiconductor chip 10 mounted therein and is made of a bendable material. In addition, the semiconductor chip 10 is connected to the substrate wiring 30 through bumps or the like. The substrate wiring 30 can be electrically connected to the outside of the package substrate 20, and can input / output electrical signals such as control signals from the outside of the package substrate 20 to the semiconductor chip 10.

  Here, the semiconductor chip 10 represents a semiconductor chip that has been subjected to the pre-process and has been separated into pieces by dicing. The package substrate 20 is made of, for example, a plastic substrate 20, and the semiconductor chip 10 can be bent by bending the plastic substrate 20.

  That is, as shown in FIG. 2, the semiconductor chip 10 can be bent after the semiconductor chip 10 is packaged on the package substrate 20. For example, when it is desired to apply a tensile stress to the entire semiconductor element forming surface of the semiconductor chip 10, the package substrate 20 is curved in a convex shape as shown in FIG. Conversely, when compressive stress is desired to be applied to the entire semiconductor element forming surface of the semiconductor chip 10, the package substrate 20 is curved in a concave shape as shown in FIG.

  As described above, by applying stress to the entire surface of the semiconductor element of the semiconductor chip 10, it is possible to apply stress to the MOSFET which is an individual semiconductor element. For example, the operating speed of the NMOS transistor can be improved by applying tensile stress to the NMOS transistor. Further, by applying compressive stress to the PMOS transistor, the operating speed of the PMOS transistor can be improved.

  Since the semiconductor chip 10 includes both NMOS transistors and PMOS transistors, only one of the transistors improves the operating speed when stress is applied to the entire semiconductor chip 10. However, normally, when tensile stress is applied to the semiconductor chip 10, the change in the operation speed of the NMOS transistor and the change in the operation speed of the PMOS transistor are greater in the improvement in the operation speed of the NMOS transistor. Therefore, even if a tensile stress is applied to the semiconductor chip 10, the operation speed can be improved in the entire semiconductor chip 10. It is also possible to bend the semiconductor chip 10 before mounting it on the plastic substrate 20, measure the change in the operating speed of the semiconductor chip 10, and bend the plastic substrate 20 accordingly.

  The package substrate 20 is curved and fixed to the board as described above. Specifically, a board for mounting the plastic substrate 20 on which the semiconductor chip 10 is mounted is prepared. The board is provided with an uneven shape in order to curve the plastic substrate 20. By mounting the plastic substrate 20 on the uneven boat, tensile stress and compressive stress can be applied to the semiconductor chip 10.

Further, the semiconductor chip 10 in the plastic substrate 20 and the wiring 40 on the board are electrically connected.

  Further, as shown in FIG. 3, the semiconductor chip 10 can be applied with tensile stress or compressive stress by mounting it on a ceramic substrate 50 having an uneven shape. Specifically, the amount of bending of the semiconductor chip is estimated in advance from measurement of the operating speed of the semiconductor chip 10 and the like, and how the semiconductor chip 10 is bent is determined. Thereafter, when a tensile stress is applied to the semiconductor chip 10, it is mounted on a ceramic substrate 50 having a convex shape, as shown in FIG. When compressive stress is applied to the semiconductor chip 10, it is mounted on a ceramic substrate 50 having a concave shape as shown in FIG.

  Here, the ceramic substrate 50 is provided with wiring 40 for exchanging with external signals, and is electrically connected to each terminal of the semiconductor chip 10. A resin 60 for fixing the semiconductor chip 10 is sealed on the ceramic substrate 50.

  The semiconductor device according to the first embodiment of the present invention configured as described above can be formed by the following manufacturing method. FIG. 4 is a flowchart showing a method for manufacturing a semiconductor device according to the first embodiment of the present invention. Hereinafter, description will be made with reference to FIGS.

  First, the pre-process is finished, and the semiconductor chip 10 separated by dicing is prepared (S11). Next, the operation speed of the semiconductor chip 10 is tested by TEG, D / S, and F / T (S12). At this time, in order to reduce the variation of the semiconductor chip 10, the direction in which the package substrate 20 is bent and the amount to be bent are estimated so as to increase the operation speed for those having a low operation speed. In addition, when the operation speed is excessive, the bending direction and the amount of bending of the package substrate 20 are estimated so that the operation speed decreases. Further, the bending direction and the bending of the package substrate 20 are measured so that the semiconductor chip 10 itself is bent, the change in the operating speed of each semiconductor chip 10 is measured, and the variation in the operating speed between the individual semiconductor chips 10 is reduced. You may estimate the quantity to make.

  Next, the semiconductor chip 10 is mounted on a package substrate 20 such as a plastic substrate (S13). Next, the package substrate 20 on which the semiconductor chip 10 is mounted is placed on the board (S14). At this time, the package substrate 20 is bent and fixed on the board according to the bending direction and the bending amount of the package substrate 20 estimated in the test of the semiconductor chip 10.

  Here, the individual semiconductor chips 10 are bent in a direction to reduce the variation due to the bending of the semiconductor chips 10. All of the semiconductor chips 10 may be curved in the direction in which the operation speed increases. At that time, the bending amount of the semiconductor chip may be adjusted so that the variation in the operation speed is reduced.

  Further, when the ceramic substrate 50 is used, after the amount of bending of the semiconductor chip 10 is estimated in step S12, the semiconductor substrate 10 is not mounted on the package substrate 20 but is formed on the ceramic substrate 50 having an uneven shape corresponding to the bending direction and amount of bending. The chip 10 may be mounted and resin sealed.

  As described above, the semiconductor device according to the first embodiment of the present invention is mounted on a plastic substrate by mounting a semiconductor chip on a plastic substrate and fixing the plastic substrate on a curved surface, or on a ceramic substrate having an uneven shape. By doing so, a tensile stress or a compressive stress can be applied to the semiconductor chip, so that it is possible to reduce the influence of variations in characteristics of the semiconductor chip.

  FIG. 5 is a block diagram of a semiconductor device schematically showing the structure of the semiconductor device according to the second embodiment of the present invention.

  The difference between the semiconductor device according to the second embodiment of the present invention and the semiconductor device according to the first embodiment is that, in the first embodiment, the semiconductor chip 10 is curved before shipment, and the influence due to the characteristic variation of the semiconductor chip 10 is reduced. However, the second embodiment is provided with a mechanism capable of adjusting the operation speed of the semiconductor chip 10 after shipment. A specific description will be given below.

  As shown in FIG. 5, the semiconductor device according to the second embodiment of the present invention includes a semiconductor chip 10 mounted on a bendable package substrate 20 and a bend adjustment device 70 that can adjust the bend amount of the semiconductor chip 10. And a control device 80 that measures the operating speed of the semiconductor chip 10, estimates the bending amount of the semiconductor chip 10 according to the operating speed, and sends a control signal to the bending adjusting device 70.

  The package substrate 20 on which the semiconductor chip 10 is mounted is fixed on the board. The bending adjusting device 70 can apply stress to the semiconductor chip 10 in accordance with a control signal from the control device 80. Here, a predetermined stress may be applied to the package substrate 20 at the time of mounting.

  In addition, the control device 80 periodically measures the operating speed of the semiconductor chip 10, and when the operating speed has deteriorated due to the use of the semiconductor chip 10, the semiconductor chip 10 increases in the direction in which the operating speed of the semiconductor chip 10 increases. A control signal is sent to the bending adjusting device 70 so as to bend.

  The semiconductor device according to the second embodiment of the present invention configured as described above can adjust the operation speed of the semiconductor device by the following operation method. FIG. 6 is a flowchart showing an operation method of the semiconductor device according to the second embodiment of the present invention. Hereinafter, description will be made with reference to FIGS. 5 and 6.

  First, at a predetermined time, the control device 80 measures the operating speed of the semiconductor chip 10 (S21). Next, the control device 80 estimates the bending amount of the semiconductor chip 10 according to the operating speed of the semiconductor chip 10 (S22). For example, when the operating speed of the semiconductor chip 10 is deteriorated, the bending amount of the semiconductor chip 10 is estimated in the direction in which the operating speed of the semiconductor chip 10 increases.

  Next, when the estimation of the bending amount of the semiconductor chip 10 is completed, the control device 80 sends a control signal for bending the semiconductor chip 10 to the bending adjusting device 70. Thereby, the bending adjusting device 70 bends the semiconductor chip 10 in a direction in which the operation speed of the semiconductor chip 10 increases (S23).

  These operations are performed periodically when a predetermined time comes, and the amount of bending is adjusted.

  As described above, the semiconductor device according to the second embodiment of the present invention can adjust the operating speed of the semiconductor chip even after shipment, and can prevent the operating speed from being lowered due to deterioration of the semiconductor chip. Moreover, since the predetermined operation speed of the semiconductor chip can be maintained for a long time, the durability of the semiconductor chip can be improved.

  Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention.

1 is a cross-sectional view of a semiconductor device schematically showing the structure of a semiconductor device according to Example 1 of the present invention. 1 is a cross-sectional view of a semiconductor device schematically showing a state where the semiconductor device according to Embodiment 1 of the present invention is mounted on a package substrate. 1 is a cross-sectional view of a semiconductor device schematically showing a state where the semiconductor device according to Example 1 of the present invention is mounted on a board. 1 is a flowchart showing a method for manufacturing a semiconductor device according to Embodiment 1 of the present invention. FIG. 6 is a block diagram of a semiconductor device schematically showing the structure of a semiconductor device according to Example 2 of the present invention. 9 is a flowchart showing a method for operating a semiconductor device according to a second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Semiconductor chip 20 Package substrate 30 Substrate wiring 40 Wiring 50 Ceramic substrate 60 Resin 70 Curvature adjusting device 80 Control device

Claims (5)

A step of preparing a semiconductor chip;
Mounting the semiconductor chip on a bendable substrate;
Bending the substrate in a direction in which the performance of the semiconductor chip is improved, and bending the semiconductor chip;
A method for manufacturing a semiconductor device, comprising: 2. The method of manufacturing a semiconductor device according to claim 1, further comprising a step of inspecting performance of the semiconductor chip. A semiconductor chip;
A bendable substrate on which the semiconductor chip is mounted;
And the semiconductor chip and the substrate are curved in a direction in which the performance of the semiconductor chip is improved. A bending adjustment mechanism for adjusting a bending amount of the semiconductor chip and the substrate;
An inspection mechanism for inspecting the performance of the semiconductor chip;
4. The semiconductor device according to claim 3, wherein the bending adjustment mechanism adjusts a bending amount of the semiconductor chip and the substrate according to a result of the inspection mechanism. The semiconductor device according to claim 4, wherein the inspection mechanism calculates a bending amount of the semiconductor chip and the substrate so that performance of the semiconductor chip is improved.

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