JP2016201490A - Plasma processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve uniformity of plasma processing.SOLUTION: A plasma processing apparatus 1 comprises: a stage 11 on which a wafer W transported by using a hand having a claw on a lateral face thereof is placed; a focus ring 12 arranged around the stage 11 and that has a notch 12b into which the claw of the hand is inserted when the wafer W is placed on the stage 11; and a chamber 13 in which the stage 11 is disposed. The chamber 13 includes a closing member 15 that has a projection part 15b for closing the notch 12b of the focus ring 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a plasma processing apparatus used when performing a wafer etching process.

  Conventionally, there is JP, 2014-007215, A as technology in such a field. In the plasma processing apparatus described in this publication, an electrostatic chuck, a focus ring provided on the outer periphery of the electrostatic chuck, and a pressing unit that presses the focus ring against the electrostatic chuck from the outside are arranged.

  The focus ring is formed with a locking portion that is recessed in the central direction over the entire circumference of the outer surface, and the contact portion of the pressing portion is locked with the locking portion. This contact portion is covered with a flange so as not to enter the field of view from the top of the focus ring. Thereby, when performing a plasma process, the contact part of a press part is not exposed to a plasma area | region. Therefore, the pressing portion is not etched, and the change in plasma distribution over time can be suppressed.

JP 2014-007215 A

However, in the above-described conventional plasma processing apparatus, when the wafer is transferred using the transfer hand, a notch is provided in advance on the focus ring for positioning the transfer hand when the wafer is placed on the stage. There is a case to leave. Here, by having a notch, there is a possibility that an air current that leaks gas from the notch is generated, and uniform processing cannot be performed.
The present invention provides a plasma processing apparatus that suppresses gas leakage from a notch formed in a focus ring and improves the uniformity of plasma processing.

A plasma processing apparatus according to the present invention includes a stage on which a wafer transported using a hand having a claw portion on a side surface is placed, and a stage around the stage, and the wafer is placed on the stage. A plasma processing apparatus comprising: a focus ring having a notch portion into which the claw portion of the hand is inserted; and a chamber in which the stage is disposed, wherein the chamber includes the focus ring. A closing member having a protrusion for closing the notch is provided.
Thereby, when performing a plasma process, the notch part of a focus ring is obstruct | occluded and generation | occurrence | production of an air current can be suppressed.

  Thereby, the uniformity of plasma processing can be improved.

1 is a perspective sectional view of a plasma processing apparatus according to a first embodiment. 1 is a perspective view of a Bernoulli hand according to Embodiment 1. FIG. 1 is an elevation view of a Bernoulli hand according to a first embodiment; It is a perspective view of the stage and Bernoulli hand before the wafer mounting concerning Embodiment 1. FIG. FIG. 3 is a perspective view of a stage and a Bernoulli hand when the wafer according to the first embodiment is placed. FIG. 3 is a perspective cross-sectional view showing a state where a notch is closed by a protrusion provided on the shield ring according to the first embodiment. FIG. 3 is a perspective sectional view of a plasma processing apparatus according to a second embodiment. It is sectional drawing of the plasma processing apparatus concerning Embodiment 2. FIG.

Embodiment 1
Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the plasma processing apparatus 1 includes a stage 11 on which a wafer W is placed, a focus ring 12 provided on the outer periphery of the stage 11 and having a notch 12b, and a stage on which the wafer W is placed. And a chamber 13 which is a processing chamber in which 11 is inserted to execute processing.

  The wafer W is placed on the stage 11 using the Bernoulli hand 2. The wafer W has a substantially disk shape, and a linear oriental flat is formed on the circumference.

  As shown in FIGS. 2 and 3, the Bernoulli hand 2 includes a substantially disc-shaped hand portion 2 a and a connecting portion 2 b that is connected to a side surface of the hand portion 2 a. The hand portion 2a has a claw portion 2c protruding downward on the side surface. For example, three claw portions 2c are arranged at equal intervals on the side surface of the hand portion 2a. When the Bernoulli hand 2 transports the wafer W, the wafer W is held in a non-contact manner by the Bernoulli effect by ejecting air from an air ejection port (not shown) provided on the lower surface of the hand portion 2a. To do. Here, one of the claw portions 2c is arranged at an oriental flat portion formed on the circumference of the wafer W, thereby restricting the rotation of the wafer W relative to the hand portion 2a.

  Further, the end of the connecting portion 2b that is connected to the hand portion 2a is connected to a drive portion (not shown) such as a motor. In the Bernoulli hand 2, the position of the hand unit 2a is changed by the operation of the drive unit. For example, the Bernoulli hand 2 operates in the horizontal direction and the vertical direction by the operation of the drive unit. As a result, the Bernoulli hand 2 can transfer the held wafer W to the stage 11, or after the wafer W is placed on the stage 11, the Bernoulli hand 2 can be retracted from above the stage 11.

  As shown in FIGS. 4 and 5, the stage 11 has a substantially columnar shape, and includes a long diameter portion 11a provided at the lower portion and a mounting portion 11b formed at the upper portion of the long diameter portion 11a with a short diameter. The wafer W transferred by the Bernoulli hand 2 is placed on the top surface of the placement unit 11b. A focus ring 12 is disposed around the mounting portion 11b. For example, the focus ring 12 may be disposed on a step formed by the long diameter portion 11a and the placement portion 11b.

  The focus ring 12 is a rectangular annular body disposed around the placement portion 11b. The upper surface 12a of the focus ring 12 is disposed at a position slightly higher than the upper surface of the mounting portion 11b. The focus ring 12 has a plurality of notches 12b provided in a groove shape extending inward and outward on the upper surface 12a side. The notches 12b are formed at three equal intervals so as to correspond to the positions of the claw portions 2c of the Bernoulli hand 2 when the Bernoulli hand 2 descends from above the stage 11.

  As shown in FIG. 1, the chamber 13 includes a chamber main body 14, a stage 11 inserted into an insertion portion of the chamber main body 14, and a shield ring 15 disposed between the chamber main bodies 14. The chamber 13 is, for example, a container that maintains an inert gas gas or reactive gas pressure in a constant reduced pressure state. In the chamber 13, plasma is generated by utilizing impact ionization between electrons accelerated by an electric field generated by a DC voltage, a high-frequency voltage, a microwave, or the like and gas molecules.

  The chamber main body 14 includes a main body portion 14a in which an insertion portion penetrating in the vertical direction is formed, and an annular protrusion portion 14b that is connected to the upper portion of the main body portion 14a and protrudes toward the insertion portion side. The insertion portion formed in the main body portion 14a is opened in a circular shape, and the stage 11 on which the wafer W is placed can be inserted from below. When the stage 11 is inserted into the insertion portion of the chamber main body 14, the upper portion of a main body portion 15a of a shield ring, which will be described later, comes into contact with the lower surface of the protruding portion 14b.

  The shield ring 15 includes a ring-shaped main body 15a and a protrusion 15b that protrudes inward from the upper portion of the main body 15a. Here, the shield ring 15 is a closing member that closes the notch 12b of the focus ring 12 by the protrusion 15b. The shield ring 15 is disposed in the insertion portion of the chamber body 14. Specifically, the outer surface 15 c of the main body portion 15 a of the shield ring 15 is in contact with the wall portion 14 c forming the insertion portion of the chamber main body 14. As for the main-body part 15a, the upper part is formed thickly in the circumferential direction, and the lower part is formed thinly. The protrusions 15b are formed at equal intervals at three locations inside the main body 15a. The inner diameter of the shield ring 15 is formed substantially the same as the outer diameter of the focus ring 12, and the inner side surface 15d of the main body portion 15a is the outer side surface 12c of the focus ring 12 when the stage 11 is inserted into the insertion portion. Abut. Thereby, the improvement of the focusing property of the plasma on the stage 11 and the electrical insulation are ensured.

  More specifically, the protrusion 15b has a shape that engages with the notch 12b of the focus ring 12 without a gap. That is, the circumferential length of the protruding portion 15b is the same as the circumferential length of the cutout of the cutout portion 12b. In addition, the length of the protrusion 15b in the inner and outer directions is the same as the length of the notch in the notch 12b in the inner and outer directions. Note that the tip 15e of the protrusion 15b may be formed to have the same R as that of the focus ring 12.

  Next, the operation of placing the wafer W on the stage 11 and the operation of setting the stage 11 on the insertion portion of the chamber body 14 will be described.

  The Bernoulli hand 2 generates an air flow on the lower surface side of the hand portion 2a and holds the wafer W in a non-contact manner by the Bernoulli effect. As a result, as shown in FIGS. 2 and 3, the Bernoulli hand 2 carries the wafer W while holding the wafer W on the lower surface side. Thereafter, as shown in FIG. 4, the hand portion 2 a is disposed above the placement portion 11 b of the stage 11.

  Next, as shown in FIG. 5, the Bernoulli hand 2 places the wafer W on the placement portion 11 b of the stage 11. At this time, the Bernoulli hand 2 is in a state in which the position of the claw portion 2c is aligned with the notch portion 12b, and the generation of the airflow from the air outlet is stopped, whereby the wafer W is lowered by gravity and the stage 11 Place on top. Thereby, the phase of the wafer W on the stage 11 can be adjusted to a predetermined direction.

  At this time, the Bernoulli hand 2 can be lowered in a state where the hand portion 2a does not interfere with the focus ring 12 by inserting the notch portion 12b and the claw portion 2c so as to be aligned. The Bernoulli hand 2 retracts from the upper part of the stage 11 after placing the wafer W on the stage 11.

  Next, the stage 11 is disposed below the chamber 13. Thereafter, the stage 11 is raised and inserted into the insertion portion of the chamber body 14.

  Here, a shield ring 15 is disposed in advance in the insertion portion of the chamber body 14. When the stage 11 is inserted into the insertion portion of the chamber body 14, the outer surface 12 c of the focus ring 12 comes into contact with the inner surface 15 d of the shield ring 15 as shown in FIG. Thereby, the periphery of the stage 11 is shielded by the shield ring 15.

  At this time, the shield ring 15 is arranged in advance such that the protrusion 15b is located at a position corresponding to the notch 12b of the focus ring 12. Therefore, when the stage 11 is inserted into the insertion portion of the chamber main body 14, the protrusion 15b is inserted into the notch 12b. Thereby, the notch part 12b will be in the state obstruct | occluded by the projection part 15b.

  Thereafter, the chamber 13 is filled with argon gas, Freon gas, or the like, and plasma processing is performed. This plasma treatment is an etching treatment for removing a silicon oxide film on the surface of the wafer W, for example.

  As a result, the notch 12b of the focus ring 12 is filled with gas onto the stage 11 while being closed by the protrusion 15b. Since the filled gas does not flow out of the cutout portion 12b, no airflow is generated on the stage 11 so that the gas flows through the cutout portion 12b. As shown by the arrows in FIG. It can be made uniform. Thereby, uniform plasma can be obtained on the wafer W, and plasma processing can be made uniform.

Embodiment 2
Next, a description will be given of a case in which a projection that closes the notch 12 b of the focus ring 12 is formed on the chamber body 14 instead of the shield ring 15. In other words, the chamber body 14 is used as a closing member. In addition, about the structural article which show | plays the function similar to the structural article used for the plasma processing apparatus 1 shown in Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIGS. 7 and 8, the plasma processing apparatus 3 includes a stage 11 on which the wafer W is placed, a focus ring 12 provided on the outer periphery of the stage 11 and having a notch 12b, and a wafer W placed thereon. And a chamber 23 into which the stage 11 is inserted.

  The chamber 23 includes a chamber main body 24 and a shield ring 25 disposed between the focus ring 12 and the chamber main body 24 at an insertion portion of the chamber main body 24. The stage 11 is inserted into the insertion portion from below the chamber body 24.

  The shield ring 25 includes a ring-shaped main body portion 25a. An outer surface 25 c of the main body portion 25 a of the shield ring 25 is in contact with a wall portion 24 d that forms an insertion portion of the chamber main body 24.

  The chamber main body 24 includes a main body portion 24a in which an insertion portion penetrating in the vertical direction is formed, and an annular protrusion portion 24b that is connected to the upper portion of the main body portion 24a and protrudes toward the insertion portion side. A protrusion 24c is formed below the tip of the protrusion 24b. When the stage 11 is inserted into the insertion portion of the chamber body 24, the protrusion 24c is inserted into the cutout portion 12b of the focus ring 12.

  Thereby, the notch 12 b of the focus ring 12 is closed by the protrusion 24 c formed in the chamber body 24. Thereafter, the chamber 23 is filled with argon gas, Freon gas, or the like, and plasma processing is performed.

  At this time, the notch 12b of the focus ring 12 is closed by the protrusion 24c, so that the gas filling the stage 11 does not flow out of the notch 12b. Therefore, on the stage 11, the flow rate of the gas to be filled can be made uniform. Thereby, a uniform plasma can be obtained in the stage 11, and the plasma processing can be made uniform. Thus, not the shield ring 25 but the chamber body 24 can be used as a closing member that closes the notch 12b.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention. For example, the notch portions 12c of the focus ring 12 have been described as being formed at three equal intervals, but the number and position are not limited thereto. Further, it is desirable that the protrusion 24c provided on the chamber body 24 shown in the second embodiment has a shape that matches the notch 12c of the focus ring 12. That is, the protrusion 24 c is formed with the same length in the circumferential direction and in the inner and outer directions as the notch 12 c of the focus ring 12. Further, the protrusion 24 c may be formed so that a portion arranged in the inner direction of the focus ring 12 has the same R as that of the focus ring 12.

DESCRIPTION OF SYMBOLS 1, 3 Plasma processing apparatus 2 Focus ring 2a Hand part 2b Connection part 2c Claw part 11 Stage 11a Long diameter part 11b Mounting part 12 Focus ring 12a Upper surface 12b Notch part 12c Outer side surface 13 Chamber 14 Chamber main body 14a Main body part 14b Protrusion part 14c Wall 15 Shield Ring 15a Main Body 15b Projection 15c Outer Side 15d Inner Side 15e Tip 23 Chamber 24 Chamber Main Body 24a Main Body 24b Projection 24c Projection 24d Wall 25 Shield Ring 25a Main Body 25c Outer Side

Claims (1)

A stage on which a wafer transported using a hand having a claw on the side surface is placed;
A focus ring that is disposed around the stage and has a notch into which the claw portion of the hand is inserted when the wafer is placed on the stage;
A chamber in which the stage is disposed, and a plasma processing apparatus comprising:
The chamber includes a closing member having a protrusion that closes the notch of the focus ring.
Plasma processing equipment.

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