JP2006135000A - Manufacturing method for semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a manufacturing method for a semiconductor device capable of inhibiting a collision between a gate electrode and a foreign matter. <P>SOLUTION: In the manufacturing method for the semiconductor device, wafers formed on a surface are arranged inside the periphery of a disk in the semiconductor device with the gate electrode, and ions are implanted to the surfaces of the wafers while rotating the disk. In the manufacturing method for the semiconductor device, photo resists as dummies in heights corresponding at a collision angle to the gate electrode of the foreign matter are formed on isolation oxide films in the wafers, the peripheral sections of the wafers or dicing sections. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method of manufacturing a semiconductor device in which a wafer on which a semiconductor device having a gate electrode is formed is arranged on the inner periphery of a disk and ions are implanted into the surface of the wafer while rotating the disk.

  In a batch type ion implantation apparatus, wafers are arranged inside the periphery of a disk, and ions are implanted into the surface of the wafer while rotating the disk (see, for example, Patent Document 1). At this time, in order to suppress the high temperature of the wafer due to ion implantation, it is necessary to rotate the disk at a high speed to generate a centrifugal force and to bring the wafer into close contact with the disk surface.

  Therefore, the wafer revolves at a speed proportional to the rotational speed (angular speed) of the disk and the size (radius) of the disk. For example, when the rotational speed of the disk is 1200 revolution / min and the distance from the disk center to the wafer center is 600 mm, the rotation speed of the wafer center is about 80 m / sec.

JP 2003-77789 A

  As described above, since the wafer revolves at high speed during ion implantation, when the separated foreign matter approaches the wafer, the foreign matter and the wafer collide at high speed. Then, as shown in FIG. 7, when a semiconductor device having an elongated gate electrode 12 is formed on the surface of the wafer 11 and the gate electrode 12 is not covered with the photoresist, the gate electrode 12 collides with the foreign matter 13. It suffers mechanical damage. Further, depending on the width (gate length) and height of the gate electrode, there is a problem that a part of the gate electrode is cut off and disconnected.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a semiconductor device manufacturing method capable of suppressing collision between a gate electrode and a foreign substance.

  A method of manufacturing a semiconductor device according to the present invention is a method of manufacturing a semiconductor device in which a wafer on which a semiconductor device having a gate electrode is formed is arranged inside the periphery of the disk, and ions are implanted into the surface of the wafer while rotating the disk. , A dummy photoresist having a height corresponding to the collision angle of the foreign matter with the gate electrode is formed on the isolation oxide film in the wafer, the peripheral portion of the wafer, or the dicing portion. Other features of the present invention will become apparent below.

  According to the present invention, collision between a gate electrode and a foreign substance can be suppressed.

Embodiment 1 FIG.
A method of manufacturing a semiconductor device according to the first embodiment of the present invention will be described with reference to FIG.

  First, a semiconductor device having the gate electrode 12 is formed on the surface of the wafer 11. Next, an oxide film (isolation oxide film) used for element isolation in the wafer 11 is formed in a dummy photoresist 14 having a height higher than that of the gate electrode 12 by a photoresist coating, exposure and development process, and the peripheral portion of the wafer. Or formed on the dicing part. However, as the dummy photoresist 14, it is preferable to use a water-soluble negative resist having good adhesion to the isolation oxide film and high mechanical strength.

  Then, the wafers 11 are arranged inside the periphery of the disk, and ions are implanted into the surface of the wafer while rotating the disk. When the foreign matter 13 released at this time approaches the wafer 11, the foreign matter 13 collides with the wafer 11 at a velocity vector V3 obtained by adding the velocity vector V1 due to the fall of the foreign matter 13 and the velocity vector V2 due to the rotation of the disk.

  Therefore, the height of the dummy photoresist 14 is set to a height corresponding to the collision angle of the foreign material 13 with the gate electrode 12, thereby causing the foreign material 13 to collide with the dummy photoresist 14. That is, the dummy photoresist 14 is used not as a dopant mask for selective ion implantation but as a wall for preventing the collision of the foreign material 13. As a result, the number of foreign matters 13 entering the gate electrode 12 can be reduced or eliminated, and collision of the foreign matter 13 with the gate electrode 12 can be suppressed.

Specifically, the collision angle of the foreign material 13 with respect to the gate electrode 12 with respect to the horizontal direction is θ, the distance between the gate electrode 12 and the dummy photoresist 14 is d ₁ , the height of the gate electrode 12 and the dummy photoresist 14. If the height difference is d ₂ , the height of the dummy photoresist 14 may be set so as to satisfy the following relational expression.
[Equation 1]
d ₂ > d ₁ tanθ (Formula 1)
However, the height of the dummy photoresist 14 is set in consideration of the contraction effect by ion implantation. When the rotation speed of the wafer 11 is 83 m / sec, the collision angle θ of the foreign material 13 with respect to the gate electrode 12 is 5 ° or less.

  In addition, when the dummy photoresist 14 is formed on the dicing portion, it is most preferable to form the dummy photoresist 14 on all four sides of the quadrilateral chip. You may form only in the dicing part of one side of a direction side.

  Although the case where the photoresist is not used as a dopant mask has been described in the above embodiment, the present invention is not limited to this. That is, the photoresist used for selectively implanting the N-type and P-type dopants in the ion implantation of the source / drain regions of the CMOS transistor can also be used for foreign matter prevention. For example, in the case of a foreign matter incident angle of 1 ° and a resist and gate electrode height difference of 230 nm, the distance between resists corresponding to the wafer speed is set according to FIG. A layout is formed so as to form a gate electrode.

Embodiment 2. FIG.
A method of manufacturing a semiconductor device according to the second embodiment of the present invention will be described with reference to FIG. In the second embodiment, instead of forming a dummy photoresist, as shown in FIG. 3, the gate electrode 12 is formed and the dummy gate electrode 15 is formed on the isolation oxide film 16 in the wafer 11 at the same time. This is different from the first embodiment.

  Since the dummy gate electrode 15 is formed in the same process as that of the gate electrode 12, it is not necessary to add a new process. Further, since the isolation oxide film 16 protrudes from the other surface of the wafer 11, the dummy gate electrode 15 formed on the isolation oxide film 16 is higher than the gate electrode 12. For this reason, the foreign material 13 is caused to collide with the dummy gate electrode 15 to reduce or eliminate the number of the foreign material 13 that penetrates to the gate electrode 12, thereby suppressing the foreign material 13 from colliding with the gate electrode 12.

Embodiment 3 FIG.
A method of manufacturing a semiconductor device according to the third embodiment of the present invention will be described with reference to FIG. First, as in the first and second embodiments, a wafer having a semiconductor device having a gate electrode formed on the surface is arranged inside the periphery of the disk.

  However, in the third embodiment, the mounting direction of the wafer on the disk is set so that the total length of the gate electrode projected in the rotating direction of the disk is minimized. For example, in the case of FIG. 4C in which the gate electrode 12 is parallel to the rotation direction of the disk, the gate projected in the rotation direction of the disk is compared to the case of FIGS. 4A and 4B. The total length of the electrode 12 is reduced. Thereafter, as in the first and second embodiments, ions are implanted into the surface of the wafer while rotating the disk.

  By reducing the total length of the gate electrode projected in the disc rotation direction in this way, the probability that the foreign material 13 collides with the gate electrode 12 is reduced, so that the foreign material 13 is prevented from colliding with the gate electrode 12. be able to.

  If a plurality of gate electrodes are formed on the wafer and their orientations are irregular, the wafer on the disk is minimized so that the total length of all gate electrodes projected in the disk rotation direction is minimized. Set the mounting direction.

Embodiment 4 FIG.
FIGS. 5A and 5B are a top view and a cross-sectional view showing a state in which a wafer is mounted on a disk in the method of manufacturing a semiconductor device according to the fourth embodiment of the present invention. As shown in the figure, a wall 18 of variable height is provided only on the side wall on the rotational direction side of the portion of the disk 17 where the wafer 11 is mounted.

  Then, the wafer on which the semiconductor device having the gate electrode is formed is arranged inside the periphery of the disk, and ions are implanted into the surface of the wafer while rotating the disk. However, the wall 18 is made higher than the gate electrode 12 when ions are implanted. Thereby, the collision of the foreign material 13 with the gate electrode 12 can be suppressed.

Embodiment 5. FIG.
FIG. 6 is a diagram showing the relationship between time and disk rotational speed in the semiconductor device manufacturing method according to the fifth embodiment of the present invention and the conventional manufacturing method.

  In the fifth embodiment as well, as in the conventional case, a wafer on which a semiconductor device having a gate electrode is formed is arranged inside the periphery of the disk, and ions are implanted into the surface of the wafer while rotating the disk at a first speed.

  However, in the fifth embodiment, the disk is rotated with the wafer mounted for a certain period of time at a second speed lower than the first speed before ion implantation. Thereby, the foreign material on the disk can be removed toward the inner wall of the chamber by centrifugal force. However, the foreign matter collides with the wafer during this low-speed rotation, but the momentum is small so that the gate electrode is not damaged. Therefore, when the disk is rotated at high speed during ion implantation, collision of the foreign material 13 with the gate electrode 12 can be suppressed.

  For example, for a gate electrode having a height of 160 nm and a width of 60 nm, the disk can be rotated for a fixed time at a rotational speed of 400 rpm (the rotational speed at the time of ion implantation is 1200 rpm) before ion implantation. .

Embodiment 6 FIG.
In the sixth embodiment, first, a wafer on which a semiconductor device having a gate electrode is formed is arranged on the inner periphery of the disk. Then, ions are implanted into the surface of the wafer while rotating the disk. However, at the time of ion implantation, the inside of the ion implantation apparatus, specifically, the entire sidewall of the implantation chamber is kept at −20 ° C. or lower. As a result, the adsorption rate of the generated foreign matter to the side wall of the injection chamber is increased and the Brownian motion of the foreign matter is reduced, so that the collision of the foreign matter with the gate electrode can be suppressed.

It is sectional drawing which shows the semiconductor device which concerns on Embodiment 1 of this invention. It is a figure which shows the relationship of the distance between resists according to the wafer speed for suppressing the collision to the gate electrode of the foreign material in the case of the foreign material incident angle of 1 degree, and a resist and gate electrode height difference of 230 nm. It is sectional drawing which shows the semiconductor device which concerns on Embodiment 2 of this invention. It is a figure which shows the relationship between the mounting direction of the wafer on a disk, and the length of the gate electrode projected on the rotation direction of a disk. In the manufacturing method of the semiconductor device concerning Embodiment 4 of the present invention, it is a top view (a) and a sectional view (b) showing a state where a wafer is mounted on a disk. It is a figure which shows the relationship between time and disk rotation speed in the manufacturing method of the semiconductor device which concerns on Embodiment 5 of this invention, and the conventional manufacturing method. It is sectional drawing which shows a mode that a foreign material collides with the gate electrode on a wafer.

Explanation of symbols

11 Wafer 12 Gate electrode 13 Foreign material 14 Photoresist 15 Gate electrode 16 Isolation oxide film 17 Disk 18 Wall

Claims (7)

In a method for manufacturing a semiconductor device, a semiconductor device having a gate electrode formed on a surface thereof is arranged on the inner periphery of a disk, and ions are implanted into the surface of the wafer while rotating the disk.
A dummy photoresist having a height corresponding to a collision angle of a foreign substance with the gate electrode is formed on an isolation oxide film in the wafer, a peripheral portion of the wafer, or a dicing portion. Production method.   The method of manufacturing a semiconductor device according to claim 1, wherein a water-soluble negative resist is used as the dummy photoresist. In a method for manufacturing a semiconductor device, a semiconductor device having a gate electrode formed on a surface thereof is arranged on the inner periphery of a disk, and ions are implanted into the surface of the wafer while rotating the disk.
A method of manufacturing a semiconductor device, wherein a dummy gate electrode is formed on an isolation oxide film in the wafer simultaneously with forming the gate electrode. In a method for manufacturing a semiconductor device, a semiconductor device having a gate electrode formed on a surface thereof is arranged on the inner periphery of a disk, and ions are implanted into the surface of the wafer while rotating the disk.
A method of manufacturing a semiconductor device, wherein the mounting direction of the wafer on the disk is set so that the total length of the gate electrodes projected in the rotation direction of the disk is minimized. In a method for manufacturing a semiconductor device, a semiconductor device having a gate electrode formed on a surface thereof is arranged on the inner periphery of a disk, and ions are implanted into the surface of the wafer while rotating the disk.
A height-variable wall is provided only on the side wall on the rotational direction side of the portion of the disk where the wafer is mounted,
A method of manufacturing a semiconductor device, wherein the wall is made higher than the gate electrode when ion implantation is performed. In a method of manufacturing a semiconductor device, a semiconductor device having a gate electrode formed on a surface thereof is arranged on the inner periphery of a disk, and ions are implanted into the surface of the wafer while rotating the disk at a first speed.
A method of manufacturing a semiconductor device, wherein the disk is rotated while the wafer is mounted at a second speed lower than the first speed for a predetermined time before ion implantation. In a method for manufacturing a semiconductor device, a semiconductor device having a gate electrode formed on a surface thereof is arranged on the inner periphery of a disk, and ions are implanted into the surface of the wafer while rotating the disk.
A method of manufacturing a semiconductor device, wherein the inside of an ion implantation apparatus is kept at -20 ° C. or lower when ion implantation is performed.

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