JPH02111015A - Chemical vapor growth apparatus - Google Patents

Abstract

PURPOSE:To make a film thickness of a film formed at a peripheral part of a wafer uniform by a method wherein an opening used to blow a reaction gas is made at a wafer holder. CONSTITUTION:A wafer holder 6 is composed of a framework of frame members 61 having hollow parts 63. A plurality of mounting grooves 61a used to hold a wafer 1 are formed at inside faces of the frame members 61; openings 61b connected to the hollow parts 63 are made near the individual mounting grooves 61a; a reaction gas 5 is introduced into the hollow parts 63 and is blown off from the openings 61b. The frame members 61 constituting the wafer holder 6 function as reaction-gas supply tubes; the reaction gas 5 is supplied also from coupling parts of the mounting grooves at a peripheral part of a wafer; accordingly, a creeping shortage of the reaction gas 5 by an influence of the frame members 61 is not caused. Thereby, it is possible to obtain a uniform thin film up to a peripheral edge part of the wafer 1.

Description

[Detailed Description of the Invention] [Summary] Chemical vapor deposition (CV) used in the manufacturing process of semiconductor devices
D) Regarding the equipment, the purpose is to provide a chemical vapor deposition equipment that achieves uniform film thickness on the periphery of the wafer by providing an opening in the wafer holder through which reactive gases are blown out. A chemical vapor deposition apparatus in which a wafer holder is placed in a reaction chamber and a reactive gas is introduced to grow a reaction product on the wafer. A plurality of mounting grooves for holding wafers are formed on the inner surface of the crosspiece member, and an opening communicating with the hollow part is provided near each of the 'fa mounting grooves, and a reactive gas is introduced into the hollow part. The configuration is such that the gas is introduced and blown out from the opening.

[Industrial application field]

The present invention relates to a chemical vapor deposition (CVD) apparatus used in the manufacturing process of semiconductor devices.

Recently, the diameter of semiconductor wafers has been rapidly increasing (8 inφ or more) in order to improve the mass production of semiconductor devices. Since the film thickness distribution within the wafer is poor for wafers of this diameter, there is a strong demand for improvement in the film thickness distribution.

[Conventional technology]

FIG. 3 is a schematic side sectional view showing a conventional general horizontal real-wall chemical vapor deposition apparatus.

In the figure, a plurality of wafers 1 are arranged substantially vertically on a wafer holder 2 made of quartz with grooves cut at predetermined intervals, and placed inside a cylindrical reaction chamber 3 made of quartz. 4 heats the wafer 1 to a predetermined temperature of about 300 to 900° C. in a resistance heating furnace. After the inside of the reaction chamber 3 is reduced in pressure by an exhaust pump, a reaction gas 5 is introduced into the reaction chamber 3 from one end, and a reaction product grows on the surface of the wafer 1 to form a predetermined thin film. .

FIG. 4 shows the wafer holder 2 used in the conventional chemical vapor deposition apparatus described above, in which (a) is a front view and (b) is a top view. A semi-cylindrical framework is formed, and a plurality of wafer mounting grooves 21a are provided at predetermined intervals on the inner peripheral surface of the crosspiece member, and the mounting grooves 21
A plurality of wafers were placed at predetermined intervals by engaging the peripheral edge of the wafer 1 with the wafer a.

[Problem to be solved by the invention]

In the conventional technology, a reaction gas is introduced into the entire reaction chamber at once from one supply port, and is then diffused and supplied to the surfaces of a plurality of wafers.

For this reason, it is difficult for the reaction gas to flow around to the details, and especially at the peripheral edge of the wafer, the shadow of the crosspiece may be hidden in the mounting groove of the crosspiece of the wafer holder or in the shadow of the crosspiece. appeared large, and the film thickness became locally thin, resulting in a film thickness distribution on the wafer surface.

For this reason, a good product (semiconductor chip) cannot be obtained in the portion where the film thickness is reduced, resulting in a problem that the yield in the film forming process is reduced.

The present invention has been created to address the above-mentioned problems, and is a chemical vapor deposition apparatus that aims to uniformize the film formed on the periphery of the wafer by providing an opening in the wafer holder through which a reactive gas blows out. The purpose is to provide

[Means to solve the problem]

The above problem is solved by a chemical vapor deposition apparatus in which a wafer holder on which a wafer is placed is placed in a reaction chamber, and a reactive gas is introduced to grow a reaction product on the wafer. The frame member has a plurality of mounting grooves for holding the wafer formed on the inner surface thereof, and an opening communicating with the hollow portion is provided near each of the mounting grooves, This problem is solved by the chemical vapor deposition apparatus of the present invention, which is configured to introduce a reaction gas into the hollow part and blow it out from the opening.

[Effect]

The crosspiece that makes up the wafer holder acts as a reactive gas supply pipe, and the reactive gas is also supplied from the mounting groove engagement part on the wafer periphery, so there is no shortage of reaction gas going around due to the shadow of the crosspiece. A uniform thin film can be obtained up to the periphery of the process.

〔Example〕

The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic side sectional view of a chemical vapor deposition apparatus of the present invention, and FIG. 2 is a diagram of a wafer holder used in the present invention.

In FIG. 1, the chemical vapor deposition apparatus of the present invention includes a substantially cylindrical reaction chamber 3 and a plurality of wafers 1 placed in the reaction chamber 3.
A wafer holder 6 is arranged inside the wafer holder 6. Reaction chamber 3
The reaction gas 5 is supplied into the interior through two gas supply pipes 5 whose flow rates are independently controlled by flow rate control systems 51 and 52.
3.54, it is supplied in two systems. One gas supply pipe 53 is a conventional supply port that opens at the end face of the reaction chamber 3 and diffuses gas throughout the reaction chamber, and the other gas supply pipe 54 is opened inside the introduction part 65 of the wafer holder 6. Most of the reaction gas from this supply pipe 54 flows through the hollow part 63 through the introduction port 62 at the right end of the crosspiece member 61 of the wafer holder 6, as will be described later, while a part of it flows through the hollow part 63. It is consumed while being blown out from the wafer mounting m 61 a to the peripheral edge of the wafer 1 as shown by arrow B, and the remainder is discharged from the discharge port 64 at the left end.

FIG. 2 is a perspective view showing an example of the wafer holder used above.

The wafer holder 6 is made of a quartz member, and has a gas introduction part 65 in the shape of a substantially semicircular cylinder with a bottom and a terminal part 66 in the shape of a semicircular plate.
It has a structure in which three rod-shaped crosspiece members 61 each having a hollow part 63 are framed, and one end of the crosspiece member 61 is opened at the bottom of the gas introduction part 65, and the other end is opened at the terminal end 66. connected to. Mounting grooves 61a for holding the peripheral edge of the wafer 1 are provided on the inner surface of each crosspiece member 61 at predetermined intervals.

The wafer holder 6 is arranged in the reaction chamber such that the open end of one gas supply pipe 54 is located within the semi-cylindrical introduction part 650 at one end of the wafer holder 6, so that the introduction part 65 functions as a funnel and the gas supply pipe 54 Most of the reaction gas 5 supplied from
It flows into the hollow part 63 of 1.

Next, A-
The opening from which the reactant gas blows out will be explained using the enlarged cross section A.

A hollow portion 6 is provided on the wall surface of the wafer R placement groove 61a of the crosspiece member 61.
3 is provided with an opening 61b that communicates with the hollow part 63.
A part of the reaction gas 5 flowing through is divided and blown out from each opening 61b as shown by arrow B, and placed? It is designed to be supplied to the peripheral edge of the wafer 1 that is engaged with the i 61 a.

The remainder of the reaction gas that has flowed through the hollow portion 63 of each crosspiece member 61 is discharged into the reaction chamber from the discharge port 64 of the terminal end portion 66. (See Figure 1) As described above, the chemical vapor deposition apparatus of the present invention has two systems for supplying the reactive gas. Since supplementary gas from a separate system using the holder as a gas supply pipe is separately supplied near the holder holding part at the periphery of the wafer, by adjusting the flow rates of both gas supply systems to the appropriate side, the shadow of the wafer holder frame can be reduced. The reactant gas can be sufficiently supplied to the entire wafer, and it is possible to form a reaction product having a uniform thickness distribution up to the periphery even on a large diameter wafer.

〔Effect of the invention〕

As explained above, according to the chemical vapor deposition apparatus of the present invention,
It is possible to grow a thin film having a good thickness distribution within the wafer, including the peripheral edge, while eliminating the adverse effects of the wafer holder, thereby improving the yield in the manufacturing process of semiconductor devices.

Figure 1 is a schematic side sectional view of the chemical vapor deposition apparatus of the present invention; Figure 2 is a diagram of a wafer holder used in the present invention; Figure 3 is a schematic side view of a conventional chemical vapor phase reaction apparatus; The figure shows a conventional wafer holder.

In the figure, 1 - semiconductor wafer, 2 - wafer holder, 3
...-reaction chamber, 4--resistance heating furnace, 5
-Reactive gas, 6...-Wafer holder 6
1--crosspiece member, 61a-mounting groove, 61b
-・-opening, 62-inlet, 63-・
Hollow part, 64-Exhaust port.

[Brief explanation of the drawing]

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Claims (1)

[Claims] A wafer holder (6) on which a wafer (1) is placed is placed in a reaction chamber (3), and a reactive gas (5) is introduced to deposit reaction products on the wafer (1). A chemical vapor deposition apparatus for growth, wherein the wafer holder (6) is composed of a framework of a crosspiece member (61) having a hollow part (63), and the crosspiece member (61) holds the wafer (1). A plurality of mounting grooves (61a) are formed on the inner surface, and an opening (61b) communicating with the hollow part (63) is provided near each of the mounting grooves (61a), and the hollow part (63) A chemical vapor deposition apparatus characterized in that it is configured to introduce a reactive gas (5) into the reactor gas and blow it out from the opening (61b).