TWI752671B - Injector of vertical furnace for low pressure chemical vapor deposition (lpcvd) system - Google Patents

Abstract

The present invention provides an improved design for the gas injector of a semiconductor production equipment - vertical furnace, and there are two main effects as follows: (a) when the reacting gas is output into a reaction chamber (tube) through the injector, it may diffuse more uniformly throughout the reaction chamber, and thereby the uniformity of the film deposited on the wafer surface can be improved; and (b) since the new-type injector of the present invention is made with new technology, it can reduce particles during the diffusion process and prevent pipeline blockage which results from formation of a large amount of powder.

Description

Injectors for vertical furnace tubes for low pressure chemical vapor deposition (LPCVD) systems

The present invention relates to gas injectors, in particular to gas injectors for vertical furnace tubes of low pressure chemical vapor deposition (LPCVD) systems.

Furnace tube equipment is widely used in semiconductor manufacturing processes, such as diffusion, oxidation, and heat treatment; among them, the diffusion process mainly uses the injector in the furnace tube equipment to introduce special gas into the cavity, and the inside of the cavity A reaction occurs on a substrate (eg, a semiconductor wafer) to form a thin film. When films are produced by diffusion processes, it is generally desirable to achieve deposition with better film uniformity and less particle generation.

As mentioned above, in the diffusion process, the reaction gas needs to be introduced into the furnace tube cavity through the injector, and the reaction gas should be diffused onto the substrate to form the desired thin film. Therefore, the distribution of the reaction gas in the furnace tube is very important. As the name suggests, the reactor of the vertical furnace tube is configured in an upright manner. In the conventional vertical furnace tube, the reaction gas system is introduced into the furnace tube (cavity) through an injector with a horizontal output end. However, the gas injector of this design makes it impossible for the reaction gas to achieve the best diffusion effect in the furnace tube cavity, so the quality of the produced film may not be ideal. Common non-ideal conditions include poor film uniformity and excessive generation of particles.

It is against this background that the present invention arises.

In view of this, according to an embodiment of the present invention, a gas injector for a vertical furnace tube is provided, which is composed of two pipe parts: the first pipe part has an input end of the injector, and the second pipe part has an injector The output end of the two pipes is a fluid connection with a 90-degree angle formed by processing methods. The gas injector is arranged such that the first pipe body part is horizontally installed at the gas input end of the vertical furnace tube, and the second part extends along the extending direction of the vertical furnace tube. In addition, the output end of the second pipe body has an inclined surface, and the opening of the inclined surface is inclined from the inside to the outside and from the top to the bottom in the radial direction of the vertical furnace tube. Therefore, the integral injector is generally disposed between the inner wall of the vertical furnace tube and the wafer boat carrying the wafers.

In one embodiment, the gas injector is made of quartz material. In one embodiment, the angle between the inclined plane and the horizontal plane is between 30° and 60°. In one embodiment, the angle between the inclined plane and the horizontal plane is about 45°. In one embodiment, the first body portion is substantially perpendicular to the second body portion.

According to an embodiment of the present invention, a vertical furnace tube is provided, which includes an outer tube, an inner tube, a wafer boat, and a plurality of gas injectors. The inner tube is arranged inside the outer tube. The wafer boat is arranged inside the inner tube and used for carrying wafers. In one embodiment, a plurality of the gas injectors are arranged side by side with a predetermined distance from each other. In one embodiment, the vertical furnace tube includes three gas injectors, wherein the lengths of the second body portions of each of the gas injectors are about 500 mm, about 850 mm, and about 1050 mm, respectively. In one embodiment, the gas injectors are arranged side by side in order from shortest to longest.

Other aspects of the present invention will become more apparent from the following detailed description in conjunction with the accompanying drawings.

The objects, advantages and features of the present invention will become more apparent from the following detailed description of several embodiments and the accompanying drawings.

In the following description, numerous specific details are set forth in order to provide a clearer understanding of the embodiments of the present invention. However, the disclosed embodiments may be practiced even in the absence of some or all of these details. In some instances, well-known structures and operations have not been described in detail to avoid unnecessarily obscuring the disclosed embodiments. Although numerous specific details are set forth for the purpose of explanation, it should be understood that they are not intended to limit the disclosed embodiments. When specific embodiments are described in relative terms (eg, "upper" and "lower," "top" and "bottom," "inner" and "outer," etc., these terms are Not intended as a limitation. Furthermore, it is to be understood that the various embodiments shown in the figures are schematic and not necessarily drawn to scale.

FIG. 1 is a schematic diagram of a vertical furnace tube 100 according to an embodiment of the present invention. As understood by those of ordinary skill in the art, the vertical furnace tube 100 may be used in a low pressure chemical vapor deposition (LPCVD) system. As shown in FIG. 1 , the vertical furnace tube 100 includes an outer tube 102 , an inner tube 104 , a wafer boat 106 , a gas injector 108 , a base 110 , and a gas supply part 112 . The inner tube 104 is disposed in the outer tube 102, and the outer tube 102 and the inner tube 104 are arranged in concentric circles, and the outer tube 102 and the inner tube 104 are separated by a predetermined distance. In some embodiments, the outer tube 102 and the inner tube 104 are made of quartz material. In addition, the wafer boat 106 is disposed in the inner tube 104 and on the base 110, and is used for horizontally carrying the wafers to be processed thereon. In some embodiments, the boat 106 is made of quartz. The gas injector 108 is used to deliver one or more reaction gases from the gas supply part 112 to the interior of the vertical furnace tube 100 . Various embodiments of the gas injector 108 of the present invention will be described below with reference to FIGS. 2 and 3 .

2 and 3 show a side view and a perspective view of the gas injector 108, respectively, according to an embodiment of the present invention. The gas injector 108 includes a first tubular portion 122 and a second tubular portion 132, wherein the first tubular portion 122 has an input end 124, the second tubular portion 132 has an output end 134, and the first tubular portion 122 In fluid connection with the second body portion 132 . In some embodiments, the first body portion 122 is substantially perpendicular to the second body portion 132, ie, the gas injector 108 is substantially L-shaped. It should be understood, however, that the first body portion 122 need not be perpendicular to the second body portion 132 . When installed in a vertical furnace tube, the input 124 is fluidly connected to the gas supply 112 so that the desired one or more reaction gases can be delivered from the gas supply 112 through the input 124 and the output 134 to the inside the vertical furnace tube 100 and further diffuses onto the wafers located on the wafer boat 106 . The gas injector 108 is arranged in the manner shown in FIG. 1 , so that the second tube body portion 132 is located between the inner tube 104 of the vertical furnace tube 100 and the wafer boat 106 , and the second tube body portion 132 is along the vertical axis. The extending direction of the furnace tube 100 extends. In addition, the output end 134 of the second tube portion 132 has an inclined surface 136 , and the inclined surface 136 is inclined downward from the inside to the outside in the radial direction of the vertical furnace tube 100 .

By using a gas injector 108 having a beveled output end inclined in the above manner, the uniformity of diffusion of the reaction gas can be improved and undesirable particles on the wafer can be reduced. In a preferred embodiment, the angle between the inclined plane 136 and the horizontal plane is between 30° and 60°. In another preferred embodiment, the angle between the inclined plane 136 and the horizontal plane is about 45°.

In some embodiments, the gas injector 108 may be made of quartz (eg, quartz of GE214, GE224). However, it should be understood that the gas injector 108 may be made of any other suitable material. In addition, the gas injector 108 may be machined to have smooth surfaces on the inner and outer tube walls, and may be machined to round out sharp and/or sharp corners.

In some embodiments, a plurality of gas injectors 108 may be included in the vertical furnace tube 100, and the gas injectors 108 may be arranged side by side at a predetermined distance from each other, eg, about 50 mm apart. In order to distribute the reaction gases more evenly in the vertical furnace tube 100, the second body portion 132 of each of the gas injectors 108 may have different lengths. For example, the gas injectors 108 may be arranged side by side in order from short to long. In a particular embodiment, three gas injectors 108 are included in the vertical furnace tube 100, and the lengths of the second body portion 132 of each of the gas injectors 108 are about 500 mm, about 850 mm, and about 500 mm, respectively. 1050mm.

Compared with the conventional gas injector of the vertical furnace tube (the output end of which is a horizontal plane), the present invention adopts the gas injector 108 having a sloped output end, so the following advantageous effects can be obtained: When transported into the vertical furnace tube 100, the diffusion uniformity of the reaction gas is improved, thereby improving the thickness uniformity of the deposited film; and the particles on the wafer generated during processing can also be reduced, thereby reducing wafer defects. reduce.

Although the foregoing embodiments have been described in detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. It should be noted that there are many alternative ways to implement the method and apparatus of the present embodiments. Accordingly, the present embodiments should be regarded as illustrative rather than restrictive, and the present embodiments should not be limited to the specific details set forth herein.

It is to be understood that the structures and/or methods described herein are exemplary in nature and that these particular embodiments or examples are not to be regarded as limiting as various changes are possible. The particular operations or methods described herein may represent one or more of any number of processing schemes. Accordingly, the various operations described may be performed in the order described, in other orders, in parallel, or in some instances omitted. Similarly, the order of the above operations may be changed.

The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various processes and structures, and other features, functions, acts, and/or properties disclosed herein, and any and all equivalents thereof.

100: Vertical furnace tube 102: Outer tube 104: Inner tube 106: Crystal Boat 108: Gas injector 110: Pedestal 112: Gas Supply Department 122: The first body part 124: input terminal 132: Second body part 134: output terminal 136: Bevel

The described embodiments and their advantages will be more fully understood with reference to the following detailed description taken in conjunction with the accompanying drawings. These drawings are not intended to limit changes in form and detail of the described embodiments that may be made by those skilled in the art without departing from the spirit and scope of the embodiments.

FIG. 1 is a schematic diagram of a vertical furnace tube according to an embodiment of the present invention.

Figure 2 shows a side view of a gas injector according to one embodiment of the present invention.

3 shows a perspective view of a gas injector according to an embodiment of the present invention.

In the drawings of the present invention, reference numerals may be reused to designate similar and/or identical elements.

100: Vertical furnace tube

102: Outer tube

104: Inner tube

106: Crystal Boat

108: Gas injector

110: Pedestal

112: Gas Supply Department

Claims (10)

A gas injector for a vertical furnace tube, comprising: a first body portion having an input end; and a second body portion having an output end, the first body portion being fluidly connected to the second body portion, Wherein the gas injector is arranged so that the second tube body part is located between the inner tube of the vertical furnace tube and the wafer boat for carrying wafers, and the second tube body part is along the vertical furnace tube The extension direction of the tube extends, and the output end of the second tube body portion has an inclined surface, and the inclined surface is inclined downward from the inside to the outside in the radial direction of the vertical furnace tube. The gas injector for a vertical furnace tube as claimed in claim 1, wherein the gas injector is made of quartz material. The gas injector for a vertical furnace tube as claimed in claim 2, wherein the angle between the inclined plane and the horizontal plane is between 30° and 60°. The gas injector for a vertical furnace tube of claim 2, wherein the angle between the inclined plane and the horizontal plane is about 45°. The gas injector for a vertical furnace tube of claim 2, wherein the first tube body portion is substantially perpendicular to the second tube body portion. A vertical furnace tube, comprising: an outer tube; an inner tube disposed inside the outer tube; a wafer boat, disposed inside the inner tube and used for carrying wafers; and A plurality of gas injectors as claimed in any one of claims 1 to 5. The vertical furnace tube of claim 6, wherein a plurality of the gas injectors are arranged side by side with a predetermined distance from each other. The vertical furnace tube of claim 7, wherein the vertical furnace tube includes three of the gas injectors. The vertical furnace tube of claim 8, wherein the lengths of the second body portion of each of the gas injectors are about 500 mm, about 850 mm, and about 1050 mm, respectively. The vertical furnace tube according to any one of claims 7 to 9, wherein the gas injectors are arranged side by side in an order from short to long.

Images