Epitaxy apparatus

Abstract

An epitaxy apparatus (10) comprises a supply portion (110) comprising inlet pipes (1111, 1112, 1113) for introducing gases (15) in a first horizontal direction, an inlet distribution portion (120) for laterally distributing the gases (15) received via the supply portion (110). The inlet distribution portion (120) comprising distribution chambers (1211, 1212, 1213). The epitaxy apparatus (10) further comprises an inlet channel portion (125) comprising inlet channels (1261, 1262, 1263). The inlet channels (1261, 1262, 1263) feed the gas received from the distribution chambers (1211, 1212, 1213) to a reactor chamber (130). The inlet distribution portion (120) comprises a distribution element ( 1221( 1222, 1223) comprising a horizontal element (123) extending in a second horizontal direction and a plurality of vertical elements (124), a first side of each of the vertical elements (124) being connected to the horizontal element (123) at different horizontal positions, respectively, the horizontal element (123) being connected to a corresponding one of the inlet pipes (1111, 1112, 1113). A second side of each of the vertical elements (124) is connected to a corresponding one of the inlet channels (1261, 1262, 1263) at different horizontal positions.

Description

[0001] EPITAXY APPARATUS Metalorganic vapor-phase epitaxy (MOVPE) or metalorganic chemical vapor deposition (MOCVD) is a chemical vapor deposition method which is e.g. used for depositing high-quality crystalline compound semiconductors which are used in the manufacture of optoelectronic devices such as light-emitting diodes (LEDs) and laser diodes. For example, a mixed gas of one or more group III raw material gases and one or more group V raw material gases may be supplied to a reactor chamber. It is an objective of the present disclosure to provide an improved epitaxy apparatus. According to embodiments, the above object is achieved by the claimed matter according to the independent claims. SUMMARY According to embodiments, an epitaxy apparatus comprises a supply portion comprising inlet pipes for introducing gases in a first horizontal direction. The epitaxy apparatus further comprises an inlet distribution portion for laterally distributing the gases received via the supply portion, the inlet distribution portion comprising distribution chambers associated to the inlet pipes, respectively. The epitaxy apparatus further comprises an inlet channel portion comprising inlet channels associated to the distribution channels, the inlet channels feeding the gas received from the distribution chambers to a reactor chamber. The inlet distribution portion comprises a distribution element comprising a horizontal element extending in a second horizontal direction intersecting the first horizontal direction and a plurality of vertical elements, a first side of each of the vertical elements being connected to the horizontal element at different horizontal positions, respectively. The horizontal element is connected to a corresponding one of the inlet pipes, and a second side of each of the vertical elements is connected to a corresponding one of the inlet channels at different horizontal positions. For example, the inlet pipes may be arranged in a central portion of a corresponding one of the horizontal elements, respectively. According to embodiments, a distance between neighbouring vertical elements may be constant. According to embodiments, at least one of the distribution chambers may comprise a flow restrictor for constraining a flow of the gas in the distribution chamber. For example, the flow restrictor may comprise a perforated plate comprising holes extending in the first horizontal direction. According to embodiments, a porosity of the perforated plate may be larger than 0.4 and smaller than 0.6. According to further embodiments, the flow restrictor may comprise a labyrinth having a passing direction along the first horizontal direction. By way of example, the distribution element may be implemented as a bore hole in a rigid block. According to embodiments, the reactor chamber may be arranged at a position exclusively shifted in the first horizontal direction from the supply portion. For example, the arrangement of supply portion, inlet distribution portion and inlet channel portion may be linear in the first horizontal direction. According to further embodiments, an epitaxy apparatus comprises a supply portion comprising inlet pipes for introducing gases in a first horizontal direction and an inlet distribution portion for laterally distributing the gases received via the supply portion, the inlet distribution portion comprising distribution chambers associated to the inlet pipes, respectively. The epitaxy apparatus further comprises an inlet channel portion comprising inlet channels associated to the distribution channels, the inlet channels feeding the gas received from the distribution chambers to a reactor chamber. At least one of the distribution chambers comprises a flow restrictor for constraining a flow of the gas in the distribution chamber. For example, the flow restrictor may comprise a perforated plate comprising holes extending in the first horizontal direction. According to embodiments, a porosity of the perforated plate may be larger than 0.4 and smaller than 0.6. According to further embodiments, the flow restrictor comprises a labyrinth extending along the first horizontal direction. The accompanying drawings are included to provide a further understanding of embodiments of the invention and are incorporated in and constitute a part of this specification. The drawings illustrate the embodiments of the present invention and together with the description serve to explain the principles. Other embodiments of the invention and many of the intended advantages will be readily appreciated, as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numbers designate corresponding similar parts. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1A shows a schematic cross-sectional view of components of an epitaxy apparatus. Fig. 1B is a schematic cross-sectional view of further components of the epitaxy apparatus. Fig. 1C is a schematic perspective view of an inlet distribution portion. Fig. 2A is a perspective view of an epitaxy apparatus comprising a labyrinth. Fig. 2B is a cross-sectional view of an example of a labyrinth. Fig. 3A is a perspective view of a portion of an epitaxy apparatus comprising perforated plates. Fig. 3B is a perspective view of a perforated plate. Fig. 3C is a perspective view of a portion of a further epitaxy apparatus comprising perforated plates. Fig. 3D is a perspective view of a further epitaxy apparatus comprising perforated plates. DETAILED DESCRIPTION In the following detailed description reference is made to the accompanying drawings, which form a part hereof and in which are illustrated by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology such as "top", "bottom", "front", "back", "over", "on", "above", "leading", "trailing" etc. is used with reference to the orientation of the Figures being described. Since components of embodiments of the invention can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope defined by the claims. The description of the embodiments is not limiting. In particular, elements of the embodiments described hereinafter may be combined with elements of different embodiments. The terms “lateral” and “horizontal” as used in this specification intends to describe an orientation parallel to a first surface of a substrate or semiconductor body. This can be for instance the surface of a wafer or a die. The term “vertical” as used in this specification intends to describe an orientation which is arranged perpendicular to the first surface of a substrate or semiconductor body. Fig. 1A is a schematic vertical cross-sectional view of an epitaxy apparatus according to embodiments. The epitaxy apparatus 10 comprises a supply portion 110 which comprises several inlet pipes 1111… 1113for introducing reactant gases in a first horizontal direction, e.g. the x-direction. For example, different reactant gases such as metalorganic gases may be fed via the inlet pipes 1111… 1113, respectively. The epitaxy apparatus 10 further comprises an inlet distribution portion 120 which comprises distribution chambers 1211… 1213that are associated to the inlet pipes, respectively. For example, the inlet distribution portion 120 may be implemented as a steel block in which the single distribution chambers 121 may be arranged, e.g. as corresponding cavities. Each of the inlet pipes 1111… 1113is associated to a corresponding one of the distribution chambers 1211… 1213. The epitaxy apparatus further comprises an inlet channel portion 125 which comprises a plurality of inlet channels 1261… 1263. Each of the inlet channels 1261… 1263is associated and connected to a corresponding one of the distribution chambers 1211… 1213. For example, the inlet channels 1261… 1263may be implemented by fused silica plates that may be arranged in a tapered manner so that a diameter of the inlet channels 1261… 1263decreases in a flow direction of the gas 15. The inlet channels 1261… 1263feed the gas received from the distribution chambers 1211… 1213to a reactor chamber 130. For example, a susceptor 132 for supporting a wafer 131 may be arranged in the reactor chamber 130. As is clearly to be understood, although three inlet pipes, distribution chambers and inlet channels are illustrated in the Figures, any arbitrary number of these elements may be employed. For example, the reactor chamber 130 may be arranged at a position exclusively shifted in the first horizontal direction from the supply portion 110. This feature is intended to mean that according to embodiments, the reactor chamber 130 is arranged on one side of the supply portion 110 only. For example, according to these embodiments, the reactor chamber 130 does not surround the supply portion 110. For example, the arrangement of supply portion 110, inlet distribution portion 120 and inlet channel portion 125 may be linear in the first horizontal direction. This feature is intended to mean that according to embodiments, the reactor chamber 130 is arranged on one side of the supply portion 110 only. For example, according to these embodiments, the reactor chamber 130 does not surround the supply portion 110. Fig. 1B is a perspective view of elements of the epitaxy apparatus 10 comprising the supply portion 110 comprising the plurality of inlet pipes 1111, … 1113, the inlet distribution portion 120 and the inlet channel portion 125. As is shown in Fig. 1B, the inlet distribution portion 120 may further comprise a distribution element 1221, … 1223for distributing a gas flow fed by a respective inlet pipe 111 along a second horizontal direction, e.g. the y direction. The distribution element 122 comprises a horizontal element 123 which extends in the second horizontal direction, e.g. the y-direction and a plurality of vertical elements 124. A first side of each of the vertical elements 124 is connected to the horizontal element 123 at different horizontal positions along the second horizontal direction. A distance between neighbouring vertical elements 124 may be constant among the vertical elements 124. The different horizontal positions may comprise a starting position and an end position of the horizontal element 123. As a consequence, the vertical elements 124 may be uniformly distributed at the largest possible distance among neighbouring vertical elements 124. The horizontal element 123 is connected to a corresponding one of the inlet pipes 1111… 1113. Further, a second side of each of the vertical elements 124 is connected to a corresponding one of the inlet channels 1211, … 1213. For example, the vertical elements 124 may extend downward or upward from the horizontal element 123. As is shown in Fig. 1B, the distribution element 123 may have a shape like a rake. The horizontal element 123 is connected with the inlet pipe 111. For example, the inlet pipe 111 may be positioned in a central portion of the horizontal element 123. The distribution element 123, i.e. the horizontal element 123 and the vertical elements 124 may be formed as boreholes within the inlet distribution portion 120, e.g. the inlet steel block. As a consequence, the epitaxy apparatus 10 may be easily implemented by simply exchanging the inlet steel block by an inlet steel block that additionally comprises the distribution element 123. Accordingly, a gas supplied via the inlet pipe 111 is distributed along the second horizontal direction. The flow of gases is made more uniform along the second direction resulting in an improved process control and reproducibility. As a result, the gas flow becomes laminar resulting in a homogeneous distribution of gases flowing via the inlet channel 126 to the reactor chamber 130. Accordingly, all regions of the wafer(s) inside the reactor chamber 130 experience approximately the same growth conditions. As a consequence, the growth behavior across the wafer is made more uniform. For example, the number of vertical elements 124 may be larger than 3. For example, the number of vertical elements 124 may be smaller than 15. For example, the number of vertical elements 124 may be approximately 6 to 10, for example 8. A length of the horizontal element 123 measured in the second horizontal direction may be approximately equal to a width of the distribution chamber 121 measured in the second horizontal direction. For example, the length of the horizontal element 123 may be larger than 0.8 * w or 0.9 * w, wherein w denotes the width of the distribution chamber 121. For example, a diameter of a bore hole of the horizontal element 123 may be equal to a diameter of the inlet pipe 111. A diameter of a bore hole of the vertical elements 124 may be equal or approximately equal to a bore hole of the horizontal element 123. As is illustrated in Figs. 1B and 1C, the horizontal positions of the vertical elements 124 may be arranged along a line parallel to an outer boundary of the associated distribution chamber 121. For example, the outer boundary may be parallel to the second horizontal direction, e.g. the y-direction. Further, the vertical elements 124 may be arranged adjacent to the outer boundary of the associated distribution chamber, wherein the outer boundary has a smaller distance to the supply portion 110 than any other outer boundary. For example, each of the distribution chambers 1211… 1213may further comprise a flow restrictor 127, 128 that may constrain a flow of the gas 15 in the distribution chamber 1211… 1213. The flow restrictor 127, 128 may extend along the entire width and / or height of the distribution chamber 121. For example, such a flow restrictor may comprise a labyrinth 127. Fig. 2A shows a perspective view of the supply portion 110, the inlet distribution portion 120 and the inlet channel portion 125, wherein labyrinths 127 are arranged within the distribution chambers 1211, … 1213. Fig. 2B shows a vertical cross-sectional view of a labyrinth 127 along the first direction. As is shown, the labyrinth comprises vertical portions 129 that are alternatingly arranged on a bottom plate 115 or a top plate 116 of each of the distribution chambers 1211,…1213. For example, a vertical size d of the gap between a vertical portion 129 and the adjacent top plate 116 or bottom plate 115 may be larger than approximately 0.85*s. The vertical size d may be less than 0.95*s. For example, the vertical size may be approximately 0.9*s, wherein s is the vertical height of the corresponding distribution chamber 1211, 1212, 1213. For example, the vertical size d of the gap may be larger than approximately the distance f between adjacent vertical portions 129. The number of vertical elements 129 may be, for example, larger than three and may be smaller than 20. Fig. 3A shows a perspective view of components of an epitaxy apparatus 10 comprising a supply portion 110, an inlet distribution portion 120 and an inlet channel portion 125. According to embodiments, the flow restrictor may be implemented by a perforated plate 128. As is shown in Fig. 3A, the perforated plate may be arranged at different positions within the distribution chambers 1211… 1213. As is shown in Fig. 3A, for example, more than one perforated plate 128 may be arranged in the distribution chamber 1211… 1213. The perforated plate may extend in the second horizontal direction and in the vertical direction, e.g. the z direction. Fig. 3B shows a perspective view of an example of a perforated plate 128. As is shown, a plurality of holes 133 extending in a thickness direction of the perforated plate 128, e.g. the first horizontal direction are arranged in the perforated plate. For example, a thickness t of the perforated plate 128 along the first horizontal direction may be in a range of 0.5 to 2 mm, e.g. approximately 1 mm. Moreover, a radius r of the holes 133 may be larger than 0.03 mm. For example, the radius r may be less than 0.15 mm. For example, the radius may be approximately 0.075 mm. For example, a porosity may be larger than 0.4 and less than 0.6, e.g. approximately 0.5. In more detail, this may mean that the area of holes 133 may be approximately equal to 0.5 * (the area of the perforated plate 128). According to embodiments, it is not necessary that the holes 133 in the perforated plate 128 are aligned e.g. with respect to the positions of the vertical elements 124 of an associated distribution element 122i. Further, when the epitaxy apparatus comprises a plurality of perforated plates 128 assigned to one distribution chamber 121iand arranged along the first horizontal direction, it is not necessary that the holes 133 of different perforated plates 128 are aligned to each other. Due to the presence of the flow restrictor, for example, the labyrinth 127 or the perforated plate 128, the gas flow may be made more laminar and turbulences may be avoided. As is clearly to be understood, the epitaxy apparatus 10 which does not comprise the distribution element 1221, 1222, 1223as explained above, may comprise a flow restrictor. Fig. 3C shows a perspective view of a portion of the epitaxy apparatus 10, wherein a distance between the perforated plate 128 and the distribution element 122 may be smaller than the distance from the perforated plate 128 to the inlet channel 1261… 1263. Fig. 3D shows a further implementation, wherein the distance b from the distribution element 1221to the perforated plate 128 is larger than the distance from the perforated plate 128 to the inlet channel 1261… 1263. Due to the presence of the distribution element 122 and, optionally, the flow restrictor, a high degree of stability and uniformity of the flow of process gas may be ensured already inside the inlet distribution chambers 1211… 1213. As a consequence, the uniformity may be maintained in the inlet channel portion 125 and in the reactor chamber 130. Further, the process control and reproducibility of the process may be improved. While embodiments of the invention have been described above, it is obvious that further embodiments may be implemented. For example, further embodiments may comprise any subcombination of features recited in the claims or any subcombination of elements described in the examples given above. Accordingly, this spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.

[0002] LIST OF REFERENCES 10 epitaxy apparatus 15 reactant gas 110 supply portion 1111, 1112, 1113inlet pipe 115 bottom plate 116 top plate 120 inlet distribution portion 1211, 1212, 1213distribution chamber 1221, 1222, 1223distribution element 123 horizontal element 124 vertical element 125 inlet channel portion 1261, 1262, 1263inlet channel 127 labyrinth 128 perforated plate 129 vertical portion 130 reactor chamber 131 wafer 132 susceptor 133 hole

Claims

CLAIMS 1. An epitaxy apparatus (10) comprising: a supply portion (110) comprising inlet pipes (1111, 1112, 1113) for introducing gases (15) in a first horizontal direction; an inlet distribution portion (120) for laterally distributing the gases (15) received via the supply portion (110), the inlet distribution portion (120) comprising distribution chambers (1211, 1212, 1213) associated to the inlet pipes (1111, 1112, 1113), respectively; an inlet channel portion (125) comprising inlet channels (1261, 1262, 1263) associated to the distribution chambers (1211, 1212, 1213), the inlet channels (1261, 1262, 1263) feeding the gas received from the distribution chambers (1211, 1212, 1213) to a reactor chamber (130), wherein the inlet distribution portion (120) comprises a distribution element (1221, 1222, 1223) comprising a horizontal element (123) extending in a second horizontal direction intersecting the first horizontal direction and a plurality of vertical elements (124), a first side of each of the vertical elements (124) being connected to the horizontal element (123) at different horizontal positions, respectively, the horizontal element (123) being connected to a corresponding one of the inlet pipes (1111, 1112, 1113), and a second side of each of the vertical elements (124) being connected to a corresponding one of the inlet channels (1261, 1262, 1263) at different horizontal positions.

2. The epitaxy apparatus (10) according to claim 1, wherein the inlet pipes (1111, 1112, 1113)are arranged in a central portion of a corresponding one of the horizontal elements (123), respectively.

3. The epitaxy apparatus (10) according to claim 1 or 2, wherein a distance between neighbouring vertical elements (124) is constant.

4. The epitaxy apparatus (10) according to any of the preceding claims, wherein at least one of the distribution chambers (1211, 1212, 1213) comprises a flow restrictor (127, 128) for constraining a flow of the gas in the distribution chamber (1211, 1212, 1213).

5. The epitaxy apparatus (10) according to claim 4, wherein the flow restrictor comprises a perforated plate (128) comprising holes (133) extending in the first horizontal direction.

6. The epitaxy apparatus (10) according to claim 5, wherein a porosity of the perforated plate (128) is larger than 0.4 and smaller than 0.

6.

7. The epitaxy apparatus (10) according to any of the preceding claims, wherein the flow restrictor comprises a labyrinth (127) having a passing direction along the first horizontal direction.

8. The epitaxy apparatus (10) according to any of the preceding claims, wherein the distribution element (1221, 1222, 1223) is implemented as a bore hole in a rigid block.

9. The epitaxy apparatus (10) according to any of the preceding claims, wherein the reactor chamber (130) is arranged at a position exclusively shifted in the first horizontal direction from the supply portion (110).

10. The epitaxy apparatus (10) according to any of the preceding claims, wherein the arrangement of supply portion (110), inlet distribution portion (120) and inlet channel portion (125) is linear in the first horizontal direction.

11. An epitaxy apparatus (10) comprising: a supply portion (110) comprising inlet pipes (1111, 1112, 1113) for introducing gases (15) in a first horizontal direction; an inlet distribution portion (120) for laterally distributing the gases (15) received via the supply portion (10), the inlet distribution portion (120) comprising distribution chambers (1211, 1212, 1213) associated to the inlet pipes (1111, 1112, 1113), respectively; an inlet channel portion (125) comprising inlet channels (1261, 1262, 1263) associated to the distribution chambers (1211, 1212, 1213), the inlet channels (1261, 1262, 1263) feeding the gas (15) received from the distribution chambers (1211, 1212, 1213) to a reactor chamber (130), wherein at least one of the distribution chambers (1211, 1212, 1213) comprises a flow restrictor (127, 128) for constraining a flow of the gas (15) in the distribution chamber (1211, 1212, 1213).

12. The epitaxy apparatus (10) according to claim 11, wherein the flow restrictor comprises a perforated plate (128) comprising holes (133) extending in the first horizontal direction.

13. The epitaxy apparatus (10) according to claim 12, wherein a porosity of the perforated plate (128) is larger than 0.4 and smaller than 0.6.

14. The epitaxy apparatus (10) according to any of claims 11 to 13, wherein the flow restrictor comprises a labyrinth (127) extending along the first horizontal direction, the labyrinth comprising vertical portions (129) that are alternatingly arranged on a bottom plate (115) or a top plate (116) of each of the distribution chambers (1211,…1213).

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