JP2927211B2 - Wafer processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer processing apparatus which is one of semiconductor processing apparatuses, and more particularly to a single wafer processing apparatus for processing one wafer at a time.

[0002]

2. Description of the Related Art In a process of manufacturing a semiconductor device, a silicon wafer on a sample table is etched using gas molecules excited by thermal energy, plasma discharge or the like, or a process such as chemical vapor deposition (CVD) is performed. Is performed.

[0003] It is an airtight process chamber, charged with the wafer, the process chamber is evacuated to a vacuum, further introducing anti 応Ga scan, the plasma generated by the high frequency power ion,
Alternatively, etching, chemical vapor deposition (CVD), or the like is performed using radicals (neutral active species) or using heat from a heater or the like.

FIG. 6 schematically illustrates a conventional parallel plate type plasma etching apparatus of the conventional wafer processing apparatus, particularly, a cathode bonding type.

[0005] Electrodes 2 and 3 are provided facing each other inside the processing chamber 1, and a high-frequency power supply 4 is connected to the electrodes 2.
A wafer 6 is loaded on one of the electrodes, the cathode electrode 2 side. The electrodes 2 and 3 are cooled by a cooling system 5, and a reaction gas is introduced from a gas introduction system 7 from the other of the electrodes, the anode electrode 3.

Further, an exhaust system 8 is connected to the processing chamber 1 so as to exhaust the reaction gas. Figure
In 6 , 9 is a flow control valve, and 10 is an exhaust pump.

[0007] The plasma etching of the wafer 6
Generally, it is performed as follows. Wafer 6 is charged, it is introduced from the outer periphery of the lower surface or the anode electrode 3 of the anode electrode 3 anti 応Ga scan in a vacuum evacuated the processing chamber 1 from the gas introduction system 7. The inside of the processing chamber 1 is set to a required pressure by the exhaust system 8, and high-frequency power is applied to the cathode electrode 2 to generate plasma.

The wafer 6 contains radicals in the plasma,
Etching is performed by a synergistic effect with reactive gas ions accelerated by a self-bias voltage induced near the high-frequency electrode.

[0009]

The connection position of the exhaust system 8 to the processing chamber 1 is set at a position concentric with the cathode electrode 2 because the cooling system 5 and the like are provided at the center of the cathode electrode 2. Since it is difficult to provide it and the structure becomes complicated, it is located at a position off the center of the cathode electrode 2. The exhaust port 1 in which the exhaust system 8 communicates with the processing chamber 1
Since 1 is not concentric with the cathode electrode 2, the flow of the reaction gas near the wafer 6 concentrically loaded on the cathode electrode 2 is biased. This causes a problem in the uniformity of the wafer processing such as the etching processing of the wafer 6.

Assuming that the exhaust hole 11 is provided as shown in FIG. 7 , if the center of the wafer 6 is 0, the exhaust hole 11 side is-, and the anti-exhaust hole 11 side is +, the etching rate of the same wafer is considered. As shown in FIG. 8 , the non-uniformity is increased at the exhaust hole 11 side.

The present invention has been made in view of the above circumstances, and has an object to make the flow of a reaction gas near a wafer uniform and to improve the uniformity of wafer processing.

[0012]

According to the present invention, a wafer is loaded on a sample stage provided in a processing chamber, and the wafer is processed by utilizing gas molecules excited by thermal energy / plasma discharge in a reaction gas atmosphere. In the wafer processing apparatus, the processing chamber is partitioned into a reaction gas introduction side and a reaction gas discharge side by a flow distribution adjusting means, and the flow distribution adjusting means is rotatably provided around the sample stage. An exhaust conductance adjusting hole is provided in the baffle plate, and the circumferential cross-section of the exhaust conductance adjusting hole is continuously changed by the circumferential rotation of the baffle plate to change the flow path cross-sectional area. It is characterized in that it can be set to.

[0013]

The reaction gas flowing along the wafer is rectified by the baffle plate even when the introduction position or the discharge position of the reaction gas is not located at the center of the processing chamber and is uneven, and is uniformed over the entire surface of the wafer.

[0014]

EXAMPLES Hereinafter, FIG. 1, one embodiment of the present invention based on FIG.

In FIG. 1, the same components as those shown in FIG. 6 are denoted by the same reference numerals.

There is provided a flow rate distribution adjusting means 21 for vertically partitioning the processing chamber 1 around the cathode electrode 2. The flow distribution adjusting means 21 includes a baffle base 14, a baffle plate 17
Consists of Around the cathode electrode 2 and the processing chamber 1
The baffle base 14 provided at a boundary position between, on the baffle base 14 along on the desired pitch circle, to the required number of bored minute Chiana 13. A baffle plate 17 is superimposed on the baffle base 14 and attached to each of the dispersion holes 13. The baffle plate 17 is provided with exhaust conductance adjusting holes 16 at the same pitch as the dispersion holes 13 formed in the baffle base 14.

In this case, both the dispersion hole 13 and the exhaust conductance adjusting hole 16 have a smaller hole diameter as approaching the exhaust hole 11 and a larger hole diameter as the distance from the exhaust hole 11 increases. By rotating the exhaust conductance adjusting hole 16
Is changed.

[0018] In the first embodiment, distribution holes, exhaust conductance adjustment hole is not necessarily a circle,
The shape may be an ellipse or a rectangle.

FIGS. 3 to 5 show a second embodiment. In this embodiment, a baffle plate 18 in which the baffle plate and the baffle base are integrated is provided. The baffle plate 18 is eccentrically formed with an exhaust hole 19 larger than the cathode electrode 2. With the eccentricity of the exhaust hole 19, the exhaust hole 19 and the cathode 2
Ring-shaped exhaust conductance adjustment hole 2 formed by
0 is no longer symmetrical with respect to the electrode center, narrow at the exhaust hole 11 side as shown in FIG. 4, widens in a counter exhaust hole 11 side, the flow rate adjustment of the reaction gas are made.

Further, by rotating the baffle plate 18, the positions of the narrow portion and the wide portion of the exhaust conductance adjusting hole 20 are moved, and the state of adjusting the flow rate of the reaction gas can be changed.

In the above embodiment, it is assumed that the reactant gas is introduced from the upper electrode (in this embodiment, the anode electrode), but is introduced from the lower electrode (in this embodiment, the cathode electrode). In this case, the exhaust hole is provided on the upper electrode side, and the exhaust system is also connected to the upper electrode side.

[0022]

As described above, according to the present invention, even when the exhaust hole is provided at a deviated position other than the center, the flow of the reaction gas can be made uniform over the entire surface of the wafer, and Enables uniform processing, improves yield,
It can help improve product quality.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing one embodiment of the present invention.

FIG. 2 is a view as viewed in the direction of arrows AA in FIG. 1;

FIG. 3 is a schematic sectional view showing another embodiment.

FIG. 4 is a view taken in the direction of arrows BB in FIG . 3;

5 is a view taken in the direction of arrows BB in FIG. 3 in which the rectification state is changed.
You.

FIG. 6 is a schematic sectional view of a conventional example.

FIG. 7 is a view taken in the direction of the arrows CC in FIG . 6;

FIG. 8 shows an edge at each position of a wafer in a conventional example .
FIG. 3 is a diagram showing a ching speed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processing chamber 2 Cathode electrode 3 Anode electrode 4 High frequency power supply 6 Wafer 11 Exhaust hole 14 Baffle base 16 Exhaust conductance adjustment hole 17 Baffle plate 18 Baffle plate 20 Exhaust conductance adjustment hole 21 Flow distribution adjusting means

Claims (3)

(57) [Claims] In a wafer processing apparatus, a wafer is loaded on a sample table provided in a processing chamber, and the wafer is processed using gas molecules excited by thermal energy, plasma discharge or the like in a reaction gas atmosphere. The processing chamber is partitioned into a reaction gas introduction side and a reaction gas discharge side by a flow rate distribution adjusting means, and the flow rate distribution adjusting means has a baffle plate rotatably provided around the sample stage. An exhaust conductance adjusting hole is provided, and the flow cross-sectional area at a position along the circumferential direction of the exhaust conductance adjusting hole is continuously changed by circumferential rotation of the baffle plate, so that it can be arbitrarily set. Characterized wafer processing equipment. 2. A flow rate distribution adjusting means comprising a baffle base provided at a boundary between a reaction gas introduction side and a reaction gas discharge side and having a plurality of dispersion holes, and a baffle plate having an exhaust conductance adjustment hole. Wafer processing equipment. 3. The wafer processing apparatus according to claim 1, wherein the baffle plate has an exhaust hole eccentric with respect to the sample stage and forms a ring shape.