Step scan photo-etching machine double-platform exchanging and positioning system

[0038] The present invention will be described in detail below with reference to the drawings and specific embodiments.

[0039] Figure 5 Shows the state of the dual wafer stage positioning system of the present invention when it is working, and its structure includes a master base 1, a wafer stage positioning unit set on the master base and running at the exposure station, and a wafer stage positioning unit running at the pretreatment station. Wafer stage positioning unit, each wafer stage positioning unit includes a wafer carrier device 2a (silicon wafer carrier device of the pretreatment station), 2b (silicon wafer carrier device of the exposure station), and motion positioning detection devices 50a, 51a , 50b, 51b; x-direction guide rail 10a, or 10b, 11b; y-direction guide rail 20a, 21a or 20b, 21b, each silicon wafer carrying device is installed on x-direction guide rail, can move along x-direction guide rail, and x-direction guide rail installation It can move along the y-direction guide rail. The x-direction guide rails of the two stations can be connected. Linear gratings 40a, 49a or 40b, 41b, 49b are installed on the guide rails. The motion positioning detection device is used for the exposure process. Position measurement and feedback of the silicon wafer exposure position and the alignment position of the pretreatment station. The x-direction guide rail set at the pretreatment station is 10a, from Figure 7-1 3 Look, the upper and lower x-direction rails of the exposure station are 10b and 11b respectively. In addition, it also includes cable stations 30a, 30b, which move through cable station guide rails 39a, 39b arranged on both sides of the main base.

[0040] Such as Figure 5 At this time, the dockable x-direction linear guide 10a and the silicon wafer carrying device 2a are set at the pretreatment station, and the x-direction linear guide 10b and another silicon wafer carrying device 2b are set at the exposure station for exposure Work, where the x-direction linear guide 11b is at the edge of the silicon wafer stage, does not interfere with the exposed stage, and is temporarily idle. The cable tables 30a, 30b are driven by the driving device arranged inside them, so that the cables on the silicon wafer carrying device keep moving in synchronization with the silicon wafer carrying devices 2a, 2b.

[0041] The silicon wafer carrying device 2a, 2b of the present invention and the guide rails 10a, 10b, 11b, and the guide rails 10a, 10b, 11b and the guide rails 20a, 21a, 20b, 21b adopt frictionless air bearings, and some parts adopt vacuum preheating. As the preload method of air bearing, permanent magnet preload can also be used as required.

[0042] The guide rails of the present invention are equipped with linear gratings 40a, 49a, 40b, 41b, 49b, respectively. The gratings 40a, 40b, 41b can be used as position feedback devices of the two silicon wafer carrying devices 2a, 2b along the x direction. Linear gratings 49a, 49b can be used as a position feedback device for the silicon wafer carrying devices 2a, 2b along the y direction. For the center exposure position of the exposure station and the alignment position of the pretreatment station, laser interferometer detection systems 50a, 51a, 50b, 51b are used as position measurement feedback devices. The position of the exchange process of the two stations is additionally controlled by auxiliary sensors.

[0043] Figure 6 It shows the working process of the double wafer stage. In the photolithography process, according to current practice, the time for the upper and lower wafers and the alignment time of the wafer and the inspection time of the exposed area topography of the wafer are less than the exposure of the entire wafer. Therefore, the process of two-stage work can be optimized to the steps shown in the flowchart, and the detailed structure layout can be seen Figure 7-12.

[0044] In the figure, the stage of the temporary pretreatment station is called 2a, and the stage of the exposure station is called 2b. At the beginning of the operation, see step 200. Both stations have no silicon wafers. At this time, 2b is in an idle state, and 2a is moved to the upper and lower positions to load the film, and then data acquisition for alignment, focusing and leveling is performed. See details Figure 7. The position detection is fed back by linear gratings 40a, 49a and laser interferometers 50a, 51a.

[0045] Step 210, see Figure 8 After the silicon wafer pretreatment of the silicon wafer carrying device 2a is completed, move to the exchange position. At this time, the two guide rails of the exposure station and the silicon wafer carrying device 2b also move to the exchange position to realize the docking of the guide rail 10a and the guide rail 11b. It is detected and controlled by linear grating and sensor.

[0046] Step 220, see Picture 9 Then, the linear motor drives the silicon wafer carrier device 2a to move from the pretreatment station to the exposure station to complete the exchange of the preprocessed silicon wafer stages.

[0047] Step 230, see Picture 10 , The guide rail of the pretreatment station quickly moves to the position where the exposed silicon wafer stage 2b in the exposure station is located, and the docking between the guide rail 10a and the guide rail 10b is realized to guide the wafer carrier device 2b to move from the exposure position to the pretreatment station. Bit.

[0048] Step 240, see Picture 11 , The silicon wafer carrying device 2b is driven by the linear motor to move from the exposure station to the pretreatment station. The two rotate to complete the action.

[0049] Step 250, see Picture 12 , The wafer carrier device 2b moves to the upper and lower wafer positions of the pre-alignment station, removes the exposed wafers, and loads new wafers, and then moves to the alignment position to perform a series of setting actions; at the same time, the silicon wafers The sheet carrying device 2a is driven by the guide rail 11b to perform an exposure operation at the exposure position, and the guide rail 10b moves to the edge position and is temporarily idle.

[0050] In step 260, the silicon wafer of the silicon wafer carrier device 2a is exposed and moved to the exchange position; at the same time, the pre-processed 2b is also moved to the exchange position to realize the docking between the guide rails 10a and 10b, which is driven by a linear motor, and 2b is from the pre-processing The processing station moves to the exposure station. The detailed graphic description is similar to Figure 7 Exchange position Figure 8-9.

[0051] In step 270, the guide rail 10a of the pretreatment station guides the silicon wafer carrier 2b to move to the exposure station, and then quickly moves to the other end of the base to realize the docking with the guide rail 11b. At this time, the silicon wafer carrier 2b is waiting for exposure. The detailed graphic description is similar to Picture 10.

[0052] Step 280, the linear motor drives the silicon wafer carrying device 2a to move from the exposure station to the pretreatment station, and then a series of settings such as loading, alignment, focusing and leveling measurement can be performed; the silicon wafer carrying device 2b The exposure operation is performed under the driving of the guide rail 10b. The detailed graphic description is similar to Figure 11-12.

[0053] Step 290, after the pretreatment of the 2a stage is completed, wait for the wafer of the 2b stage to be exposed. When the 2b stage is exposed, it will move to the exchange position respectively. The guide rail 10a of the pretreatment station is docked with the temporarily idle guide rail 11b of the exposure station to perform the stage. Mobile exchange. Step 220 is repeated to complete the continuous silicon wafer exposure in this cycle.

[0054] The specific embodiments of the present invention have been described above, but the present invention is not limited to the movement and positioning of silicon wafers in semiconductor lithography. Specifically, it can be used for any device that requires precise positioning and realizes the exchange of two devices that can work in parallel. Or system. Therefore, although the preferred embodiments of the present invention have been disclosed, those skilled in the art will realize that without departing from the scope of the present invention disclosed in the claims, any various modifications, additions and substitutions belong to The protection scope of the present invention.