The present invention relates to a device for processing substrates, in particular semiconductor wafers, with a first processing unit and a substrate holder that is vertically movable above the first processing unit, and furthermore relates to a method for processing substrates, in particular semiconductor wafers, in which a substrate holder carrying a substrate is moved into a processing position above a first processing unit, a first substrate processing is performed, and the substrate holder is raised vertically after the first substrate processing.
Apparatus and methods of this type are known, for instance, from U.S. Pat. No. 5,222,310, which has a processing bowl and a cover arranged vertically movable thereabove, which cover is embodied as a substrate holder. In the known apparatus and method, a wafer carried by the cover is introduced into the processing bowl, processed, and after the processing and subsequent raising of the cover, is removed from the cover by a substrate handling apparatus. Thus, in this apparatus it is necessary to use the substrate handling apparatus to move the wafer to an additional processing unit for a subsequent wafer processing and to use another substrate holder if one is required.
Each time the substrate is handled, however, there is a risk that it will be damaged. In addition, as a rule there is limited space available for the handling units. Furthermore, providing two independent processing units requires a large amount of space. Finally, the substrate must frequently be transported when wet, which can lead to a higher incidence of contamination problems.
Known from JP-10-4079 A is another apparatus for processing substrates. In this apparatus, a substrate to be processed is placed on a substrate holder located thereunder, which substrate holder can be moved vertically via a shaft below it. The shaft extends through the bottom of a first processing device and positions the substrate holder in the first processing device in a first step. Then the substrate holder and the substrate are raised vertically out of the first processing apparatus and a second, two-part processing device is moved from the side around the substrate holder so that a second processing apparatus is formed above the first processing apparatus. The second processing device must be sealed in the area of the shaft and in the area of the interface of the two parts of the processing device, which substantially complicates the movement control for these parts and substantially increases the costs associated therewith.
Known from DE 196 526 A are an apparatus and a method for processing substrates in a fluid container, whereby a cover for receiving the substrates can be positioned above the fluid container. The cover has a device that guides and holds the substrate, which ensures that the substrate is transported safely within the cover.
Known from JP 6-163 505 A is a semiconductor substrate cleaning apparatus in which a plurality of fixed chambers are arranged vertically one above the other and which can be sequentially fitted with substrates.
JP 10-242 106 A suggests an apparatus in which a bowl receiving a substrate can be moved along a track and can be connected to various processing fluid connections in order to perform various processing procedures within the same bowl.
Starting with the state of the art as stated in the foregoing, in particular JP-10-4079 A, the object of the present invention is therefore to provide an apparatus that reduces the handling steps between various substrate processing procedures in a simple and economical manner and that eliminates sealing problems between multi-part processing devices.
Starting with the apparatus known from JP-10-4079 A, this object is achieved in that the substrate holder is guided outside of the first and second processing units, and the second processing unit is a single or unitary part. This simplifies the structure of the processing units, since the guiding does not extend through the processing bowls and thus it is not necessary to have a seal on the shaft of the substrate holder. Furthermore, because the processing device is one, i.e. a unitary, part the sealing problems are eliminated in the area of the interface between different parts of a processing unit. The apparatus is thus simpler and more cost-effective in terms of structure. In addition, media contamination due to media adhering to the shaft is prevented.
In accordance with one embodiment of the present invention, the second processing unit can be moved in a straight line, while in another embodiment it pivots.
Advantageously, the second processing unit has a rinsing apparatus. Substrates, especially semiconductor wafers, must be rinsed frequently during a manufacturing process comprising a plurality of steps, and must especially be rinsed after certain processing steps, so that a rinsing apparatus is useful as a second processing unit above a first processing unit. In accordance with another preferred embodiment of the present invention, the second processing unit has a drying apparatus. Given a preceding wet processing procedure, it is particularly important that the substrate that has been processed is dried in a controlled manner as rapidly as possible in a drying apparatus, that is, without it first having to be transported by a handling apparatus. It is particularly advantageous when the second processing unit includes a combined rinse/dry apparatus.
In another embodiment of the present invention, one part of the substrate holder can be placed on the second processing unit. When the substrate holder comprises two parts, placing a part of the substrate holder on the second processing unit makes it possible to set down one of the parts while the other is raised in order to provide access to the substrate.
In another particularly preferred embodiment of the invention, at least one additional, third processing unit and one second substrate holder that is vertically moveable above the third processing unit are provided, whereby the second processing unit is movable in a raised position of the second substrate holder between the second substrate holder and the third processing unit. By providing a third processing unit, the movable second processing unit can be alternately used for the first and third processing unit, so that additional space savings can be achieved since the second processing unit is used with two other processing units. In addition, this results in cost savings since the need for one of the processing units is obviated.
In accordance with another embodiment of the present invention, it is also possible to provide more than two processing units, for example, arranged in a circle, which units are operated similarly one after the other by a common processing unit that is located, for instance, in the center of the other processing unit.
In order to prevent the processing procedures of the first and third processing units from affecting one another due to the mutual use of the second substrate holder, in that, for instance, contaminants from one processing unit are conveyed to the other, the first and third processing units are essentially identical. The first and third processing units can also be different when there is no risk of contamination due to the mutual use of the second processing unit.
Advantageously, the second processing unit can be moved to a rest position between the first and third processing units, in which rest position the second processing unit does not perform any processing and also does not affect or overlap the first or third processing unit. The rest position need not necessarily be situated between the first and third processing unit. It is also possible to move the second processing unit into any position in which it does not affect or overlap the first or third processing unit.
In accordance with a particularly preferred embodiment of the present invention, the first processing unit is a metal plating unit. A handling apparatus for loading and unloading the substrate holder is advantageously provided.
The object of the present invention is achieved in a method for processing substrates, in particular semiconductor wafers, that has the following method steps: moving a substrate holder carrying a substrate to a processing position above a first processing unit; performing a first substrate processing; raising the substrate holder after the first substrate processing; moving a second processing unit between the raised substrate holder and the first processing unit; and performing a second substrate processing realized in that the substrate holder is guided outside of the first and second processing units and the second processing unit is a single part. This method results in the same advantages that were enumerated in the foregoing with respect to the apparatus. Preferred embodiments of the inventive method result from the subordinate claims, again resulting in the advantages enumerated in the foregoing with respect to the apparatus.