CN103981512A - Dual-channel nozzle structure capable of controlling reactant uniform distribution - Google Patents

Abstract

The invention discloses a double-channel spout structure with controllable reactants uniformly distributed, including a first channel and a second channel. The first channel is a cylindrical channel with equal diameter or variable diameter, and the reactant gas passed through is GaCl; the second channel is located at the center of the first channel, and the gas passed through can be _N2 or a mixture of GaCl and _N2 Mixed gas; the second passage can be a section of cylindrical passage, or it can be composed of two sections, the upper section is cylindrical, the lower section is truncated circular or inverted truncated circular, and the diameter of the connection between the two sections is equal. The present invention provides a dual-channel nozzle structure with controllable reactant uniform distribution. By optimizing the gas flow in the two channels, the uniformity of the radial distribution of the reactant GaCl near the upper substrate is improved to meet the requirements of large-area substrates. The requirement for uniform growth of GaN crystal material on the bottom.

Description

A dual-channel nozzle structure with uniform distribution of controllable reactants

technical field

The invention relates to the technical field of semiconductor material growth equipment, in particular to a dual-channel spout structure for uniform distribution of controllable reactants used in hydride vapor phase epitaxy (HVPE) growth of III-V semiconductor materials (thin film or thick film). the

Background technique

With the increasingly prominent status of III-V film materials in the manufacture and development of various semiconductor devices, it has also attracted much attention in the new semiconductor material industry. However, Vapor Phase Epitaxy (VPE) technology is widely used in the preparation of semiconductor thin or thick films. Among them, Hydride Vapor Phase Epitaxy (HVPE) technology is often used in Group III nitride semiconductor materials due to its fast growth rate and low production cost. growth, especially gallium nitride (GaN) thick film growth. the

In the traditional HVPE growth system, the heated liquid metal gallium (Ga) reacts with hydrogen chloride (HCl) gas at high temperature to generate metal chloride as a group III gas, and then the metal chloride gas and the hydride of non-metallic materials Gas (such as NH ₃ ) reacts to form semiconductor material crystals (such as GaN). Usually, the NH ₃ in the reaction gas always maintains a sufficient amount, that is, the distribution of NH ₃ in the reaction chamber is uniform, and the thickness uniformity and quality of the generated product Mainly depends on the distribution of metal chlorides. However, the current vertical structure HVPE equipment usually adopts a concentric ring structure nozzle, that is, after the metal chloride is generated, it is sprayed from a cylindrical nozzle located in the center. The upper part of the substrate to be grown is distributed with a high center concentration and a low edge concentration, that is, the distribution uniformity of the metal chloride is uncontrollable. And as the market demand increases, the HVPE system must increase the output. With the further increase of the number of substrates and their area, the traditional nozzle structure is more difficult to ensure the uniformity of reactants, resulting in uneven thickness of GaN growth. For example, under the traditional concentric ring structure nozzle, due to the distribution of metal chlorides, the center concentration is high and the edge concentration is low, resulting in the GaN growth thickness showing a decreasing trend along the radial direction of the substrate, that is, the center of the substrate grows thicker, and the edge grows thicker. Thin.

The invention patent CN201310542018X discloses a precursor flow field control rod. By adding a control rod with different control ends in the center of the precursor GaCl channel, the GaCl flow field of the precursor is intervened, and it is expected to improve the uniformity of the precursor above the substrate. However, the experimental research found that the uniformity of the GaCl precursor was improved to a certain extent after the introduction of the control rod, but side reaction deposits occurred on the wall of the nozzle, which affected the quality of crystal growth. Therefore, it is still difficult to overcome the problem of uneven distribution of precursors (such as GaCl) over the substrate for high-quality growth of GaN wafers on a large effective substrate area (the precursors in this patent CN201310542018X are reactants). the

In order to improve the uniformity of the radial distribution of reactants above the substrate, it is necessary to improve the structure of the nozzle, especially the gas outlet nozzle of the metal chloride. the

Contents of the invention

In view of the deficiencies in the prior art, the main purpose of the present invention is to provide a dual-channel nozzle structure, which is mainly used to control the flow trend and distribution of the reactant gas. The dual-channel nozzle structure can make the reactant (GaCl) flow field in the The radial distribution near the upper part of the substrate is more uniform, which is conducive to uniform growth of gallium nitride on the substrate. the

In order to achieve the above objectives, the following technical solutions can be used to achieve: At present, cylindrically symmetrical suspended vertical or inverted reactors are often used in HVPE growth systems, and the GaCl channel is located in the center of the nozzle and is cylindrical. The present invention sets another gas control channel on the basis of the traditional cylindrical GaCl channel, avoids the single peak distribution characteristic of the reactant GaCl in the traditional cylindrical single channel, and improves the radial distribution uniformity of GaCl above the substrate. the

Specifically, the present invention provides a dual-channel nozzle structure with uniform distribution of controllable reactants, which is characterized in that it includes a first channel and a second channel; the two channels are concentric, and the second channel is located at the center of the first channel ; The first channel feeds gas for vapor deposition reaction reactant gas, such as GaCl; the second channel feeds gas can be N ₂ can also be GaCl and N ₂ mixed gas; the flow ratio of each gas It can be adjusted arbitrarily; the reaction gas can be combined with other reaction gases (such as NH ₃ ) to generate products after being ejected from the nozzle.

The first channel is characterized in that it is a cylindrical channel with equal diameter or variable diameter. Preferably, the outer sleeve can be composed of two sections, the upper section is cylindrical, the lower section is the skirt extension section, and the diameter of the connection between the top of the lower section and the bottom end of the upper section is equal; preferably, the outer sleeve of the first channel is also It can be composed of four sections, which are the first cylinder, the transition section, the second cylinder, and the skirt extension section from top to bottom. The second channel is characterized in that the channel is located at the center of the first channel and is cylindrical, and the length of the outer sleeve tube is slightly shorter than the length of the first channel; the second channel can also be composed of two sections, the upper section is Cylindrical, the lower section is frustum-shaped or rounded-shaped, and the diameters of the joints of the two sections are equal. the

The two first channel structures and the three second channel structures mentioned above can be cross-matched and practical according to the material growth process and specific needs. the

The present invention proposes a dual-channel nozzle structure with a controllable uniform distribution of reactants, which can improve the uniformity of radial distribution of reactants (such as GaCl) near the upper substrate, and can satisfy the uniform growth of GaN crystal materials on a larger area needs. the

The present invention will be further described below in conjunction with the accompanying drawings and embodiments. the

Description of drawings

FIG. 1 is a cross-sectional view of a dual-channel nozzle structure according to Embodiment 1 of the present invention. the

Fig. 2 is a cross-sectional view of a double-channel nozzle structure according to Embodiment 2 of the present invention. the

Fig. 3 is a cross-sectional view of a double-channel nozzle structure according to Embodiment 3 of the present invention. the

Fig. 4 is a cross-sectional view of a double-channel nozzle structure according to Embodiment 4 of the present invention. the

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention more clear, four examples are given to further illustrate the present invention. the

Embodiment one

As shown in Figure 1, a dual-channel nozzle structure with controllable reactants evenly distributed in the present invention is mainly composed of an equal-diameter cylinder 102 and a variable-section outer sleeve 105; the outer sleeve 105 and the cylinder 102 are the same Axis; the outer sleeve 105 with variable cross-section includes an upper cylinder and a lower skirt extension section, and the cross-section of the skirt extension section gradually expands from top to bottom; the outer wall of the cylinder 102 is formed with the inner wall of the outer sleeve 105 with variable cross-section The first channel 104, the reactant gas 106 passed into the first channel 104 is GaCl, the hollow part of the cylinder 102 is the second channel 101, the gas 103 passed into the second channel 101 is a mixture of GaCl and N ₂ Gas, adjust the flow rate ratio of GaCl and _N2 , and the gas flow rate in the second channel 101 and the first channel 104, optimize the uniformity of the radial distribution of the reactant GaCl gas near the top of the substrate to be grown.

Example two

The double-channel spout structure as shown in Figure 2 includes a first channel 104 and a second channel 101; the outer sleeve 105 of the first channel 104 is composed of four sections, which are sequentially from top to bottom, the first cylinder, For the transition section, the second cylinder, and the skirt extension section, the diameters of the cross-sectional circles of each section increase step by step from top to bottom, and the diameters of the joints between sections are equal, and the gas 106 introduced into the channel 104 is GaCl; the first The second channel 101 is located at the center of the nozzle structure, and the gas 103 fed into the second channel 101 is N ₂ ; between the first channel 104 and the second channel 101 is a hollow cylinder 102 of equal diameter, whose length is slightly shorter than that of the outer sleeve 105 length. Adjusting the gas flow rate of the two channels can make the radial distribution of the reactant GaCl gas near the substrate to be grown more uniform, and significantly improve the radial uniformity of the GaN crystal growth thickness.

Embodiment three

The double-channel spout structure shown in Figure 3 is based on the second embodiment, and the hollow cylinder 102 in the middle of the first channel 104 and the second channel 101 is improved. Here, the hollow cylinder 102 is composed of two sections. Its upper section is a hollow cylinder of equal diameter, and its lower section is a skirt body. The extended section is a hollow circular table tube, and the diameters of the joints of the two sections are equal; The expansion angles of the expansion sections are consistent; the length of the hollow cylinder 102 is slightly shorter than the length of the outer sleeve 105 of the channel 104 . This structure further improves the uniformity of the radial distribution of the reactant GaCl gas near the upper substrate to be grown by adjusting the gas flow of the two channels, and can eliminate the problem that the growth thickness of the crystal produced by the traditional shower head system is thick in the middle and thin at the edge . the

Embodiment four

The double-channel spout structure shown in Figure 4 is based on the second embodiment, and another improvement is made to the hollow cylinder 102 in the middle of the first passage 104 and the second passage 101, where the hollow cylinder 102 consists of two The upper section is a hollow cylinder of equal diameter, and the lower section is a hollow inverted round table tube with variable cross-section. The diameter of the junction of the two sections is equal; The thickness remains unchanged; the length of the hollow cylinder 102 is slightly shorter than the length of the outer sleeve 105 of the first channel 104 . This structure optimizes the gas flow rate of the two channels 104 and 101 to optimize the uniformity of the radial distribution of the reactant GaCl near the top of the substrate to be grown, which can eliminate the growth thickness of the crystal produced by the traditional shower head system, which is thick in the middle and thin at the edge. The problem. the

It should also be noted that the dual-channel nozzle structure with controllable reactants uniformly distributed in the present invention can be applied to both vertical HVPE systems and inverted HVPE systems. the

The above-mentioned embodiments only express some implementations of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the scope of the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the appended claims. the

Claims (6)

1. A dual-channel spout structure with uniform distribution of controllable reactants is characterized in that: it includes a first channel and a second channel; the second channel is located at the center of the first channel, and the first channel feeds gas in the gas phase A deposition reactant gas, such as GaCl; the gas fed into the second channel may be N ₂ or a mixed gas of GaCl and N ₂ . 2. The dual-channel nozzle structure according to claim 1, characterized in that: the flow ratios of the gases introduced can be adjusted arbitrarily. the 3. The reactant gas according to claim 1, characterized in that: the reactant gas can be combined with other reactant gases (such as NH ₃ ) to form products after being sprayed out of the nozzle. 4. The dual-channel nozzle structure according to claim 1, characterized in that: the first channel is a cylindrical channel with equal diameter or variable diameter. the 5. The dual-channel spout structure according to claim 1, characterized in that: the second channel can be a section of cylindrical channel, and can also be composed of two sections, the upper section is cylindrical, and the lower section is truncated circular or rounded truncated, The diameters of the joints of the two sections are equal. the 6. The dual-channel nozzle structure according to claim 1, characterized in that: the dual-channel nozzle structure can be applied to both vertical HVPE systems and inverted HVPE systems. the