JPH104065A - Single wafer processing low pressure cvd apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily form a thin film of a uniform thickness at a high growth rate. SOLUTION: The apparatus has a nozzle 10 having slit-like gas jet holes for jetting a reactive gas G approximately along the surface of a wafer 5 set in a reaction chamber R controlled under a specified low pressure condition to form a thin film on the substrate surface. The nozzle 10 is disposed sidewards and above the wafer. A resistance 105 is disposed midway in a gas passage 104 of the nozzle 10 and a rectifier 104A is provided to jet the gas from the jet holes 109 in the form of a laminar flow with a uniform width direction distribution, without dispersing in the thickness direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-wafer low-pressure CVD apparatus for forming a thin film on a wafer surface, and more particularly to an improvement in a nozzle for ejecting a reactive gas.

[0002]

2. Description of the Related Art Conventionally, a wafer is set in a reaction chamber controlled in a reduced pressure state, and a reaction gas is spouted from a slit-shaped nozzle arranged on the side of the wafer in a direction substantially parallel to the surface of the wafer. Single-wafer decompression C to form a thin film on the surface
There is a VD device. As described above, a single-wafer low-pressure CVD apparatus that forms a thin film by flowing a reaction gas from one side to the other side substantially in parallel along the wafer surface can form a thin film having a relatively uniform thickness. it can.

[0003]

However, year after year, higher uniformity of the film thickness distribution is required, and furthermore, in order to increase productivity, it is desired to improve the growth rate of the thin film. In order to make the film thickness distribution uniform, it is necessary to make the width direction distribution of the reaction gas ejected from the slit-shaped nozzle uniform,
In order to increase the growth rate by effectively using the reaction gas, it is necessary to keep the reaction gas ejected from the slit-shaped nozzle in a thinner layer without dispersing it in the thickness direction.

According to the present invention, the distribution of the reactant gas ejected from the slit-shaped nozzle in the width direction is made uniform, and is not dispersed in the thickness direction but is kept in a thin layer, so that the film thickness is made uniform and the growth rate is reduced. Sheet type decompression CV that can improve
It is intended to provide a D device.

[0005]

In order to achieve the above object, a single wafer type low pressure CVD apparatus according to the present invention sets a wafer in a reaction chamber controlled to a predetermined reduced pressure state, and In a single-wafer type low-pressure CVD apparatus for forming a thin film on a wafer surface by ejecting a reaction gas from a slit-shaped nozzle disposed laterally and above the wafer so as to substantially follow the surface of the wafer, the reaction gas is provided in the nozzle. The gas flow path has a slit-shaped gas flow path, a gas flow resistance part provided in the middle of the gas flow path, and a gas flow rectification part provided before the resistance part.

With this configuration, the flow rate of the gas flowing through the slit-shaped gas flow path is set to a predetermined flow rate at the same time as the flow rate distribution in the width direction is made uniform by the resistance section, and the gas is flown by the rectification section at the front. The gas is ejected from the gas outlet as a uniform laminar flow over the entire width. Therefore, the reaction gas ejected from the nozzle has a uniform distribution in the width direction and does not disperse in the thickness direction, and keeps a thin laminar flow. Therefore, the reaction gas uniformly and effectively acts on the entire surface of the wafer, and the film thickness distribution is made uniform and the growth rate is improved.

The resistance portion is preferably a plurality of small holes arranged along the width direction of the slit-shaped gas flow path, and is preferably formed so that the resistance value can be adjusted. Further, the resistance portion may be formed of a porous member arranged to cross the slit-shaped gas flow path.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, reference numeral 1 denotes a casing, and transparent window plates 2 and 3 made of quartz are vertically attached to each other to form a reaction chamber R. A ring-shaped susceptor 4 made of carbon is installed in the reaction chamber R, and a wafer 5 is mounted thereon. The susceptor 4 is supported by a plurality of arms 7 at the upper end of a rotating shaft 6 that extends through the lower window plate 3 into the reaction chamber R. The susceptor 4 and the wafer 5 are heated by heating devices 8 and 9 such as infrared lamps provided outside the window plates 2 and 3.
It is designed to be heated from above and below. FIG. 1 of the reaction chamber R
, A nozzle 10 is provided near the left end, and an exhaust port 11 is provided near the right end.

The nozzle 10 is disposed above and to the left of the wafer 5 in FIG. 1, and as shown in FIGS. 1 and 2, a columnar introduction portion 101 and a flat nozzle body attached to the upper end thereof. 102, and the nozzle body 102 is arranged in parallel with the surface (upper surface) of the wafer 5. The introduction section 101 is provided with a reaction gas introduction path 103, and a gas flow path 1 connected to the introduction path 103 is provided in the nozzle body 102.
04 is provided. The gas flow path 104 has a width substantially equal to the diameter of the wafer 5 in a direction along the surface of the wafer 5, and is formed in a thin slit shape in a thickness direction (the vertical direction in FIG. 1).

In the middle of the gas flow path 104, as shown in FIG. 2, a resistance portion 105 is provided. This resistance part 10
5 extend across the gas flow path 104 and
Has a protruding portion 106 formed so as to be closed. The projection 106 is provided with a plurality of semicircular recesses 107 that are open on the downstream side (the right side in FIG. 2) of the gas flow path 104. Small holes 108 are provided on the inner side of the concave portion 107, respectively.
The upstream side and the downstream side of the gas flow path 104 are connected to each other via the reference numeral 7. The cross-sectional area of the small hole 108 is formed so as to provide resistance to the flow of the reaction gas passing therethrough and to set the flow rate of the passing gas to a predetermined value.

[0011] From the downstream side of the resistance portion 105, the gas ejection port 1
The gas flow path 104A up to 09 has a predetermined cross-sectional area in relation to the gas flow rate passing through the resistance part 105, and constitutes a rectifying part for flowing the reaction gas in a laminar flow.

Next, the operation of the present apparatus will be described. While rotating the susceptor 4 and the wafer 5 by the rotation shaft 6,
These are heated to a predetermined temperature by the heating devices 8 and 9, and the reaction gas G is ejected from the gas ejection port 109 of the nozzle 10 to form a thin film on the surface of the wafer 5.

At this time, the flow of the reaction gas flowing into the gas flow path 104 from the introduction path 103 of the nozzle 10
5, a plurality of recesses 10 having a predetermined flow rate and a downstream opening from a plurality of small holes 108 provided in a predetermined distribution over the entire width of the gas flow path 104.
7 flows almost uniformly. The reaction gas flowing into these recesses 107 is supplied to the downstream gas flow path,
A flows into A and forms a flow having a uniform flow rate distribution over the entire width of the rectifying section 104A.

The reaction gas G having a uniform flow rate distribution in the width direction and flowing in the rectifying section 104A is formed into a laminar flow by the rectifying section 104A, and the gas flows from the gas outlet 109 which is the tip of the rectifying section 104A. It is gushing. Therefore, as shown in FIG. 1, the reaction gas G ejected from the nozzle 10 along the surface of the wafer 5 becomes a laminar flow that is uniform in the width direction and does not disperse in the thickness direction. Works more uniformly and effectively. Therefore, a thin film having a uniform thickness distribution is formed on the surface of the wafer 5 at a high growth rate.

FIGS. 4 and 5 show another embodiment of the present invention. A round bar 110 closing the gas flow path 104 is rotatably mounted across the gas flow path 104. The round bar 110 is provided with a plurality of through holes 111 crossing the round bar 110 along the gas flow path 104 at predetermined intervals in the width direction of the gas flow path 104. Through hole 111
The upstream end has a large-diameter hole 112 having a diameter larger than the thickness of the gas flow path 104, and the downstream end has a large diameter.
A small hole 113 having a diameter substantially equal to the thickness of the small hole 113 is formed, and an intermediate portion is tapered. In this embodiment, the round bar 11
By adjusting the rotation angle position of 0, the opening of the small hole 113 can be adjusted to adjust the resistance value of the gas flow, and a more preferable gas flow can be obtained.

FIG. 6 shows still another embodiment of the present invention, in which a rod-shaped porous member 114 is used for the resistance portion 105 and is provided so as to cross the gas flow path 104. According to this, a more reliable laminar flow can be obtained. Note that the resistance portion 105 is not limited to the above-described embodiment, and may be variously modified, such as a slit-shaped one.

[0017]

As described above, the single-wafer decompression C of the present invention is used.
According to the VD device, the widthwise distribution of the reaction gas ejected from the slit-shaped nozzle can be made uniform, and
Instead of being dispersed in the thickness direction, it can be kept on a thin layer and flow over the wafer, thereby making it possible to simultaneously achieve uniform film thickness distribution and increase the growth rate.

[Brief description of the drawings]

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

FIG. 2 is an enlarged sectional view of the nozzle taken along line AA in FIG.

FIG. 3 is a partially enlarged sectional view taken along line BB of FIG. 2;

FIG. 4 is an enlarged cross-sectional view of a nozzle showing another embodiment of the present invention.

FIG. 5 is a partially enlarged cross-sectional view taken along line CC of FIG. 4;

FIG. 6 is an enlarged sectional view of a nozzle showing still another embodiment of the present invention.

[Explanation of symbols]

 R Reaction chamber G Reaction gas 2, 3 Window plate 4 Susceptor 5 Wafer 6 Rotary shaft 7 Arm 8, 9 Heating device 10 Nozzle 11 Exhaust port 102 Nozzle body 104 Gas flow path 104A Rectifier 105 Resistor 108, 113 Small hole 109 Gas Spout 114 Porous member

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Nobuo Kashiwagi 2068-3 Ooka, Numazu-shi, Shizuoka Pref.

Claims (4)

[Claims] 1. A wafer is set in a reaction chamber controlled to a predetermined reduced pressure state, and a reaction gas is supplied to the surface of the wafer from a slit-shaped nozzle disposed in the reaction chamber and at a side and above the wafer. In a single-wafer decompression CVD apparatus in which a thin film is formed on a wafer surface by being ejected so as to substantially follow a gas flow, a slit-shaped gas flow path provided in the nozzle and a gas flow provided in the middle of the gas flow path And a gas flow rectification unit provided at the tip of the resistance unit. 2. The single-wafer, low-pressure CVD apparatus according to claim 1, wherein the resistance portion comprises a plurality of small holes arranged along the width direction of the slit-shaped gas flow path. 3. The single-wafer low-pressure CVD apparatus according to claim 1, wherein the resistance portion is formed so that a resistance value can be adjusted. 4. The single-wafer low-pressure CVD apparatus according to claim 1, wherein the resistance portion is formed of a porous member arranged so as to cross the slit-shaped gas flow path.