The invention relates to a process chamber guide, a process chamber, and a method for guiding a substrate carrier into a processing position.
For the coating of substrates, for example, for the deposition of semiconductor layers on a seed substrate, substrate carriers are used: the seed substrates are arranged on the substrate carrier. Then, the substrate carrier is moved into a processing position by a process chamber guide.
It is known to provide a lower and an upper process chamber guide for substrate carriers, so that the substrate carriers can be moved in parallel into the process chamber guides and, in the processing position, a process chamber is formed that is bounded on the side by the substrate carriers and on the top and bottom by the process chamber guides. Such a device is known from WO 2013/004851 A1.
The present invention is based on the objective of improving the previously known process chamber guide, in order to enable improved processing conditions.
This objective is achieved by a process chamber guide, a process chamber, a device for the chemical deposition of a layer on a substrate, and a method for guiding a substrate carrier into a processing position having one or more features of the invention. Advantageous constructions can be found in the description below and in the claims.
The process chamber guide is preferably designed for performing the method according to the invention, in particular, an advantageous embodiment thereof. The method according to the invention is preferably designed to be performed by the process chamber guide according to the invention, in particular, a preferred embodiment thereof.
The process chamber guide according to the invention is designed for the straight-line guidance of a substrate carrier that can be displaced into the process chamber guide in a guiding direction. In this way, by displacing the substrate carrier into a processing position, a process chamber can be bounded at least in some areas by the process chamber guide and substrate carrier.
An example of this is known from WO 2013/004851 A1 with a process chamber guide formed as a rail 3, into which a substrate carrier 1 can be moved (see FIG. 1 of WO 2013/004851 A1). The substrate carrier 1 and rail 3 bound a process chamber at least in some areas.
For the present invention, it is essential that the process chamber guide has at least one sealing surface that extends parallel to the guiding direction and is designed and arranged such that for substrate carriers arranged in the process chamber guide in the processing position, the sealing surface is spaced less than 1 mm, preferably less than 0.5 mm, in particular, less than 0.2 mm from the substrate carrier.
The invention is based on the knowledge that previous process chamber guides have disadvantages: for example, for pure sliding guides, particles that find their way into the process chamber guide can cause rough movements or can block movements of the parts. Wear debris can also be produced, which can find its way into the process chamber and can reduce the quality of the layer to be deposited. Due to the sealing surface that is spaced less than 1 mm, preferably less than 0.5 mm from the substrate carrier, a sufficient seal between the substrate carrier and process chamber guide is guaranteed, so that only minimal processing gases can escape between the substrate carrier and sealing surface.
The sealing surface is thus used for the at least approximate sealing between the process chamber guide and the substrate carrier in the processing position in the process chamber guide.
To improve the sealing effect, it is advantageous that the sealing surface has, perpendicular to the guiding direction and parallel to the surface of a substrate carrier arranged in the process chamber guide, a width of at least 2 mm, in particular, at least 10 mm, preferably at least 20 mm.
To avoid contact between a substrate carrier guided in the process chamber guide and the sealing surface, the process chamber guide is advantageously designed so that, in the processing position, the sealing surface has a spacing of at least 0.02 mm, in particular, at least 0.05 mm, preferably at least 0.1 mm to the surface of the substrate carrier facing the sealing surface.
The spacing between the sealing surface and the facing surface of the substrate carrier is preferably achieved with guide elements that can be arranged on the process chamber guide and/or on the substrate carrier. The guide elements can be constructed as guide bars, guide rollers, and/or guide channels, in particular, grooves.
The sealing surface extends in the guiding direction advantageously across a sufficient length, in order to enable the construction of a process chamber, in particular, at least across the width of a substrate carrier in the guiding direction. Preferably, the sealing surface extends at least across 0.5 m, in particular, preferably at least across 1 m.
In particular, it is advantageous that the sealing surface extends across the entire length of the process chamber guide in the guiding direction.
Advantageously, the process chamber guide has, in addition to the specified first sealing surface, at least one second sealing surface that extends parallel to the guiding direction and is designed and arranged such that for a substrate carrier arranged in the process chamber guide in the processing position, the substrate carrier is arranged between the two sealing surfaces and the sealing surfaces have a spacing, perpendicular to the guiding direction, which exceeds the thickness of the substrate carrier by less than 1 mm, preferably by less than 0.4 mm, in particular, by less than 0.2 mm. In this way, the sealing effect is increased.
Advantageously, the process chamber guide has a roller bearing for the substrate carrier. In particular, due to temperature differences during the processing, dimensional changes of the substrate carrier and/or the process chamber guide can occur, which can lead to jamming of the substrate carrier in the process chamber guide or to an insufficient seal between the process chamber guide and substrate carrier. The roller bearing avoids these disadvantages by providing good movability of the substrate carrier in the guiding direction even in the event of spatial or time temperature gradients by the roller bearing.
The roller bearing can be arranged alternatively on the substrate carrier. It is also in the scope of the invention that both the process chamber guide and also the substrate carrier have a roller bearing.
Advantageously, guide elements that interact with the roller bearing and prevent lateral displacement perpendicular to the guiding direction are provided. These guide elements can be designed as previously described as guide bars, guide rollers, and/or guide channels, in particular, grooves. Preferably, the guide elements are arranged on the element corresponding to the roller bearing: for a roller bearing arranged on the guide element, the guide elements are preferably arranged on the substrate carrier, in particular, on the side facing the roller bearing in the processing position. For a roller bearing arranged on the substrate carrier, the guide elements are preferably arranged on the process chamber guide, in particular, on the side facing the roller bearing in the processing position.
Advantageously, the process chamber guide has a groove for receiving the substrate carrier. In this way, the sealing surface can be advantageously formed in or on a side wall of the groove. Advantageously, the groove is designed as a rectangular groove. It lies within the scope of the invention that the groove could have rounded edge areas.
In particular, it is thus advantageous that one of the side surfaces of the groove, preferably both side surfaces of the groove are designed as sealing surfaces at least in some areas, advantageously across the entire length of the groove in the guiding direction.
A roller bearing is advantageously arranged on the bottom surface of the groove. Alternatively, the bottom surface of the groove is designed as a rolling surface for a roller bearing of the substrate carrier.
The present invention further relates to a process chamber for vapor deposition of layers with at least one process chamber guide according to the invention, in particular, an advantageous embodiment thereof, and at least one substrate carrier. By the displacement of the substrate carrier in the process chamber guide in a processing position, the process chamber can be bounded at least in some areas. The process chamber has end-wall bounding elements that are connected to the process chamber guide on two opposing sides.
The end-wall bounding elements are preferably arranged such that, in the processing position on two opposing sides, the process chamber is bounded on the ends by the end-wall bounding elements, while on the sides, the process chamber is bounded by the substrate carrier and the process chamber guide.
The substrate carrier preferably has a guide for rollers of the roller bearing of the process chamber guide. In particular, it is advantageous that the substrate carrier has a groove, preferably a rectangular groove for guiding the rollers of the process chamber guide. This ensures a secure guiding of the substrate carrier for movement into the process chamber guide. In particular, a lateral displacement perpendicular to the guiding direction is prevented or at least limited for the rollers by the guiding of the substrate carrier.
In another advantageous construction, the substrate carrier has a roller bearing on the side facing the process chamber guide, so that a low-friction movement of the substrate carrier in the guiding direction of the process chamber guide is achieved.
In one advantageous embodiment, the substrate carrier has a sealing bar that extends in the guiding direction and is arranged such that, in the processing position, the sealing bar is spaced by less than 0.3 mm, preferably less than 0.2 mm, in particular, less than 0.1 mm from the process chamber guide. In this way, an additional sealing and thus increase of the sealing effect between the substrate carrier and process chamber guide is achieved. In addition, this sealing bar prevents a penetration or escape of particles, in particular, into or out of a guiding groove.
Advantageously, the previously mentioned process chamber guide is arranged as a lower process chamber guide of the process chamber and the process chamber also additionally has at least one upper process chamber guide that is connected to the end-wall bounding elements and is arranged such that, in the processing position, the substrate carrier is arranged between the lower and upper process chamber guides. The upper process chamber guide is likewise designed as a process chamber guide according to the invention, in particular, as an advantageous embodiment thereof. Thus, in the processing position, a sealing effect is given on the upper and lower edges of the substrate carrier. On the front and rear edges, the process chamber is bounded by other substrate carriers arranged in front and/or in back in the guiding direction and/or by the end-wall bounding elements.
In one advantageous embodiment, the process chamber is bounded on each of two opposing sides by a substrate carrier:
Advantageously, the process chamber has the previously mentioned substrate carrier as the first substrate carrier and also at least one second substrate carrier. Furthermore, the process chamber has, in addition to lower and upper processing guides as a first process chamber guide pair, at least one additional lower process chamber guide and one additional upper process chamber guide as a second process chamber guide pair. The process chamber guides of the second process chamber guide pair are likewise designed as process chamber guides according to the invention, in particular, as advantageous embodiments thereof.
It is especially advantageous to form multiple process chambers one next to the other. Here, at least three substrate carriers parallel to each other are used, wherein the middle substrate carrier carries two-sided substrates for processing, in particular, for coating. In this way, a first process chamber is formed between the left and middle substrate carriers and a second process chamber is formed between the middle and right substrate carriers. Accordingly, the substrate carriers are guided by three lower and three upper process chamber guides.
Advantageously, the process chamber guide has at least one inlet for a flushing gas. The inlet is arranged such that, in the processing position, flushing gas can be fed in between the process chamber guide and the substrate carrier. This produces the advantage that an undesired deposition in the area between the process chamber guide and the substrate carrier and, in particular, on the roller bearing, can be avoided. Therefore, advantageously, during the process, in particular, during a deposition process, flushing gas is fed in at least during some periods, preferably continuously.
It is within the scope of the invention that flushing gas is fed in with an overpressure relative to the pressure prevailing in the process chamber, so that flushing gas can penetrate—at least minimally—into the process chamber. In this way, a penetration of gases and particles out of the process chamber into the area between the process chamber guide and substrate carrier and especially to the roller bearing is prevented in an especially effective way. Alternatively or additionally, it is advantageous to provide a flushing gas outlet, so that flushing gas can be simultaneously fed and discharged, in order to remove undesired gases or particles from the intermediate space between the process chamber guide and substrate carrier.
In the processing position, the second substrate carrier is arranged between the lower and upper process chamber guides of the second process chamber guide pair and the process chamber is thus formed by the substrate carrier, process chamber guides, and end-wall bounding elements. Here, it is within the scope of the invention that in the guiding direction, the process chamber extends across a length that is greater than the width of the substrate carrier in the guiding direction. In this case, the lateral bounding is realized by the arrangement of multiple substrate carriers one next to the other as described above, in the present construction on two opposing sides.
Advantageously, the lower process chamber guides each have a roller bearing for substrate carriers; in this way, a displacement of the substrate carriers is possible with low resistance.
In particular, it is advantageous that the upper process chamber guides each have a roller bearing, in order to also avoid frictional forces or non-uniform displacement movements due to the associated occurrence of static friction and kinetic friction in the above guides.
Advantageously, each substrate carrier has a sealing bar as described above and the sealing bars are arranged such that, in the processing position, the sealing bars are on facing sides of the substrate carrier. In this way, an especially efficient sealing is achieved.
Advantageously, all substrate carriers of the process chamber have roller bearings on all sides facing the process chamber guides, in order to enable low-friction displacement.
The invention further relates to a device for the chemical deposition of a layer on a substrate, in particular, a seed substrate, with a process chamber according to the invention as described above. Such a device has the advantages specified above.
The present invention is advantageous, in particular, for processes in which semiconductor layers and/or barrier layers are deposited chemically on the seed substrate. The present invention is especially advantageous for processes in which the deposited layer is then removed again from the seed substrate, so that a standalone layer, in particular, a semiconductor layer, is produced using the invention. The deposited layer can be, for example, a silicon layer, a layer containing silicon, such as a silicon nitride layer or silicon carbide layer, or a III-V semiconductor layer, such as a gallium-arsenide layer.
The present invention is advantageously used in the production of semiconductor layers, in particular, silicon layers, for the production of semiconductor components, in particular, large surface-area semiconductor components, such as solar cells. The present invention can also be used to cover existing semiconductor substrates, for example, silicon wafers for solar cell production, for the production of semiconductor components, in particular, large surface-area semiconductor components, such as solar cells. It is often desirable to use such processes to coat the semiconductor substrate with a barrier layer or with another semiconductor layer.
Other preferred features and embodiments will be described below with reference to embodiments and the figures. Shown therein are:
All drawings show schematic illustrations that are not drawn true to scale. The same reference symbols in
In
The process chamber guide 1 also has a projection with a sealing surface 4. The sealing surface 4 extends parallel to the guiding direction and is designed and arranged such that, in the processing position according to the illustration in
The length of the process chamber guide in the guiding direction is dependent on the device in which the process chamber guide is intended to be used, in particular, on the desired length of a process chamber to be formed by the process chamber guide. In the present case, the length of the process chamber guide is 5 m. In the guiding direction, the sealing surface 4 extends across the full length of the process chamber guide and thus also has a length of 5 m. A process chamber is thus bounded laterally by multiple substrate carriers arranged one behind the other in the process chamber guide.
The substrate carrier 2 has multiple holders for seed substrates (in the present case, silicon wafers) on a processing side that is, according to the first embodiment, the side opposite the sealing surface 4 in the processing position and thus the left side according to
While in use, in the processing position, a process chamber is formed that represents a three-dimensional enclosed space with other components not shown in
A typical process for such a device is the deposition of a semiconductor layer on the seed substrate 5, in particular, a seed substrate formed as a silicon wafer with porosified surface, in particular, an epitaxial deposition. Here, gas exchange between the process chamber (left side of substrate carrier 2) and the outside area (right side of substrate carrier 2) should be avoided.
Due to the sealing surface 4, on one side it is now guaranteed that there is no direct mechanical contact between the sealing surface 4 and substrate carrier 2 and thus displacement of the substrate carrier 2 by the roller bearing is possible with only minimal resistance. Nevertheless, the narrow gap between the sealing surface 4 and the right side of the substrate carrier 2 facing the sealing surface 4 forms a considerable fluid resistance, so that a gas flow through this gap is avoided or at least considerably reduced.
In
In
The process chamber guide according to
The second sealing surface 4a is parallel to the sealing surface 4 and is formed with identical dimensions.
The process chamber guide according to
In addition, this embodiment has the advantage that the sealing surfaces 4 and 4a are used as a guide for the substrate carrier 2 relative to lateral displacement, that is, horizontal in
In
In the embodiment according to
The process chamber guide 1 according to
In
The process chamber guide according to
In addition, the seed substrate 2 according to
Advantageously, two respective process chamber guides are formed as one piece. This will be explained in more detail using the embodiment of a process chamber according to the invention and the illustration according to
In
The process chamber guides 1, 1a, 1b, and 1c are formed according to the process chamber guide shown in
In contrast to the previously described embodiments, for the embodiment according to
In this way, a process chamber P is formed that has, in the guiding direction, a length of approximately 5 mm and a width that corresponds approximately to the spacing of the facing surfaces of the substrate carriers 2 and 2a, in the present case, approximately 10 cm. The height of the process chamber corresponds to the distance of the lower process chamber guides to the upper process chamber guides, in the present case approximately 40 cm.
In another embodiment, the process chamber according to
Number | Date | Country | Kind |
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10 2017 106 373.0 | Mar 2017 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2018/056873 | 3/19/2018 | WO | 00 |