Semiconductor substrate cleaning system

Abstract

A modular semiconductor substrate cleaning system is provided that processes vertically oriented semiconductor substrates. The system features a plurality of cleaning modules that may include a megasonic tank-type cleaner followed by a scrubber. An input module may receive a horizontally oriented substrate and rotate the substrate to a vertical orientation, and an output module may receive a vertically oriented substrate and rotate the substrate to a horizontal orientation. Each of the modules (input, cleaning and output) has a substrate support and may be positioned such that the substrate supports of adjacent modules are equally spaced. The modules are coupled by an overhead transfer mechanism having a plurality of substrate handlers spaced the same distance (X) as the substrate supports of the modules therebelow. The transfer mechanism indexes forward and backward the distance X to simultaneously transport semiconductor substrates through the cleaning system, lifting and lowering substrates from the desired modules wafer rotation / orientation sensors, an input module cart for transporting wafers between a substrate handler of a previous tool (such as a semiconductor substrate polisher) and a substrate handler of the cleaning system are also included.

Description

[0001] This application is a continuation of U.S. patent application Ser. No. 10 / 425,260 filed Apr. 29, 2003 which is a division of U.S. patent application Ser. No. 09 / 558,815, filed Apr. 26, 2000, which claims priority from U.S. Provisional Patent Application Ser. Nos. 60 / 131,124 filed Apr. 27, 1999 and 60 / 143,230 filed Jul. 10, 1999. All of these patent applications are incorporated by reference herein in their entirety.BACKGROUND OF THE INVENTION [0002] Currently available semiconductor substrate cleaning equipment suffers from high cost per unit substrate cleaned, unreliable removal of large flat particles, and of particles located along the beveled edge of a semiconductor substrate, lack of scalability and inability to easily adapt to various processing sequences, or to changes (e.g., increases) in semiconductor substrate size. Among the many factors that contribute to substrate cleaning costs, the capital cost of substrate handlers which move semiconductor substrates between v...

AI Technical Summary

Benefits of technology

[0006] For cases where the substrates are not loaded vertically into the input module and / or are not unloaded vertically from the output module, the input and / or output modules may respectively include a mechanism for receiving a semiconductor substrate in a horizontal orientation and for rotating the semiconductor substrate to a vertical orientation and a mechanism for receiving a semiconductor substrate in a vertical orientation and for rotating the semiconductor substrate to a horizontal orientation. Likewise, to facilitate wafer handling, the input module may orient the substrate to place the substrate's flat in a known position (i.e., flat finding) such that the wafer handler will not contact the flat. In steady state operation, semiconductor substrates may be loaded to and unloaded from the system, are appropriately oriented horizontally or vertically and / or have their flats appropriately positioned while other substrates are being cleaned. System productivity therefore may be enhanced as the system need not idle during the time required for substrate load / unload and orient operations.

[0007] After semiconductor substrates are loaded to and unloaded from the system via the input module and the output module, the overhead transfer mechanism lowers the wafer handlers. In one aspect the wafer handlers are simultaneously lowered into the input module and the various cleaning modules to pick up or “grip” semiconductor substrates contained therein. Thereafter, by simply raising, indexing forward the distance X and lowering, the transfer mechanism simultaneously transfers a plurality of single substrate batches from one module to the next. The transfer mechanism ungrips the substrates, raises and returns to the home position while substrates are loaded / unloaded and oriented in the input and output modules. This process repeats until each substrate receives the desired processing and is unloaded. In this aspect, the simplicity of the simultaneous substrate transfer mechanism provides accurate yet cost effective substrate transfer.

[0008] The entirely vertical orientation of the cleaning modules requires minimal footprint, and enables the inventive cleaning system to be easily scaled. To accommodate changes in substrate size the substrate supports and wafer handlers may be adjustable. Thus, few alterations are required for change-over between cleaning substrates of differing size.

Problems solved by technology

Currently available semiconductor substrate cleaning equipment suffers from high cost per unit substrate cleaned, unreliable removal of large flat particles, and of particles located along the beveled edge of a semiconductor substrate, lack of scalability and inability to easily adapt to various processing sequences, or to changes (e.g., increases) in semiconductor substrate size.

Among the many factors that contribute to substrate cleaning costs, the capital cost of substrate handlers which move semiconductor substrates between various locations presents a significant expense.

Another significant expense arises because semiconductor substrate cleaning processes are performed within a clean room environment.

The larger the area occupied by the cleaning system (i.e., the larger the footprint) the more expensive the cleaning system is to operate, due to the high cost of clean room area.

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