JP3469697B2 - Single wafer processing method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer in a single-wafer type semiconductor manufacturing apparatus in which a wafer is processed under a heating atmosphere in a reaction chamber, such as a single-wafer low-pressure CVD apparatus. Regarding the processing method. 2. Description of the Related Art An example of a single-wafer type semiconductor manufacturing apparatus is shown in FIGS. FIG. 3 is a plan view showing an outline of a single-wafer type low-pressure CVD apparatus, and FIG. 4 is a cross-sectional view taken along the line AA in FIG. In the figure, 1 is a transfer chamber, 2 is a transfer robot, 3 and 4 are cassette chambers, 5 and 6 are process chambers (reaction chambers), 30 is a wafer, and 34 is a cassette. [0003] Two cassette chambers 3 and 4 and two process chambers 5 and 6 are connected to the side surface of the transfer chamber 1. A transfer robot 2 for transferring a wafer between the cassette chamber and the process chamber is provided inside the transfer chamber 1. A transfer robot 1 is provided between the transfer chamber 1 and the cassette chambers 3 and 4 or the process chambers 5 and 6. They are partitioned by gate valves 9, 10, 11, and 12, respectively. Cassette lifter 33 provided inside cassette chambers 3 and 4
A cassette 34 is set on the top, and the wafers 30 are stored in the cassette 34. A susceptor 41 made of carbon is provided inside the process chambers 5 and 6, and a wafer 40 is set thereon. A temperature detector 46 for detecting the internal temperature is disposed inside the process chambers 5 and 6, and a quartz glass window 45 is provided on the ceiling of the process chambers 5 and 6. Above 45, the process chamber 5,
6 is provided with an infrared lamp 43 for heating the inside. The output of the temperature detector 46 is sent to the controller 37, and the output of the infrared lamp 43 is controlled by the controller 37.
Done by [0004] Using this equipment, wafer processing is generally performed as follows. The transfer robot 2 extracts the wafer 30 from the cassette 34 in the cassette chamber 3 (or 4), transfers the wafer 30 into the process chamber 6 (or 5), sets it on the susceptor 41, and sets the predetermined After heating to the temperature, a reactive gas is supplied into the process chamber 6 (or 5) to form a thin film on the wafer surface. After the processing is completed, the wafer 40 is again transferred to the original cassette 34 in the cassette chamber 3 (or 4) by using the transfer robot 2.
Collect inside. In the single-wafer type semiconductor manufacturing apparatus, when processing wafers as described above, conventionally, the wafers 30 are sequentially processed from the top of the cassette 34 of the cassette chamber 3 (or 4) or from the bottom. It was taken out, set in the process chamber 6 (or 5), and the processing was performed sequentially. When processing is performed in such an order, when the apparatus is started up or restarted after a temporary stop, the temperature inside the process chamber has dropped, so it is necessary to raise the temperature to a predetermined temperature and stabilize it. Therefore, it is common practice to heat the inside without setting the wafer in the process chamber and set the wafer in the process chamber to start processing after the internal temperature is sufficiently stabilized. I have. However, when the wafer is set and the processing is started, a slight difference occurs in the temperature distribution of the components inside the process chamber 6 due to the presence of the wafer. It has been found that a difference appears in the processing results of the second and subsequent sheets performed subsequently without significantly lowering the temperature inside the chamber 6. That is, even if the temperature inside the process chamber 6 is increased in a state where no wafer is present and once stabilized, the situation of the heat flow inside the process chamber 6 is changed by loading the wafer. Even if the values measured by the control temperature detector 46 are the same, a difference occurs in the temperature distribution inside the process chamber 6 depending on the presence or absence of the wafer 40. For this reason, the first wafer set in the process chamber 6 which has been heated in an empty state and has a stable temperature, and the second wafer set in the process chamber 6 in a state after the previous wafer has been taken out. There is a slight difference in the temperature distribution between the subsequent wafers,
The processing result is affected. In order to deal with such a problem, a method of heating the inside of the process chamber 6 with the wafer set from the beginning to stabilize the temperature inside the process chamber 6 has been adopted. There is a difference in the thermal history between the second and subsequent wafers loaded to a place where the temperature in the process chamber 6 is already close to the predetermined temperature, and the processing result of the first wafer is also changed. The effect appears. Therefore, conventionally, when the apparatus is started, a dummy wafer is used as the first wafer, and normal processing is performed on the second and subsequent wafers. In this case, another cassette for exclusive use of a dummy wafer is provided, and a countermeasure such as taking out the dummy wafer in the cassette and processing the first sheet is adopted for the first processing. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a single-wafer type semiconductor manufacturing apparatus at the time of starting up the apparatus. Another object of the present invention is to provide a wafer processing method capable of processing all wafers as regular wafers without using a dummy wafer or the like at the time of restart after a temporary stop. A single wafer processing method of the present invention is a method of processing a wafer in a single wafer processing apparatus for processing a wafer in a reaction chamber under a heated atmosphere. When the apparatus is started up or restarted after a pause, the first wafer is set in the reaction chamber,
After the temperature distribution in the reaction chamber is stabilized, the first wafer is removed from the reaction chamber without performing the processing, and the second and subsequent wafers are sequentially set in the reaction chamber and the processing is performed. For the first wafer extracted in step (1), the processing is performed by interrupting the order between the processing of the second and subsequent wafers. When the above-mentioned single wafer processing method is adopted, the first wafer set in the reaction chamber for stabilizing the temperature inside the reaction chamber is not processed, but is temporarily
Pull out of the process chamber and allow to cool. After the temperature of the first wafer has dropped to a level equivalent to that of the second and subsequent wafers, the processing of the first wafer is performed. The order of processing the first wafer can be appropriately interrupted between the processing of the second and subsequent wafers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS When processing a wafer in a single-wafer type semiconductor manufacturing apparatus shown as an example in FIG. 3 and FIG. Wafer 4 set in chamber 6 (reaction chamber)
FIG. 1 shows a model diagram of the thermal energy received by 0. For comparison, a model diagram of thermal energy received by a wafer when a conventional method is applied to a similar apparatus is shown in FIG.
As shown in FIG. 1 and 2, the vertical axis indicates the temperature measured by the temperature detector 46 in the process chamber 6, and the horizontal axis indicates the elapsed time and the number of the wafer set in the process chamber 6. The apparatus shown in FIGS. 3 and 4 is the same as the apparatus described in the section of the related art, and thus the description thereof is omitted. As shown in FIG. 1, when the single wafer processing method according to the present invention is applied, it is necessary to stabilize the temperature distribution in the process chamber 6 when the apparatus is started up or restarted after a temporary stop. First, the first wafer is set in the process chamber 6. After the temperature distribution in the process chamber 6 is stabilized, the first wafer is extracted from the process chamber 6 without being processed, and is once collected in the cassette 30 in the cassette chamber 3. Next, the second wafer is set in the process chamber 6, and normal processing is started. While the second wafer is being processed, the first wafer extracted earlier is allowed to cool in the cassette 30 and drops to a temperature equivalent to the other wafers. For this first wafer,
After the processing of the second wafer is completed, normal processing is performed between the second and third wafers by interrupting the order (see FIG. 4). The timing at which the processing of the first wafer is interrupted is not limited to between the second and third wafers as in the above-described example. May be determined in consideration of the time required for sufficiently lowering and stabilizing, and the convenience of the operation of the apparatus for processing the third and subsequent wafers. As shown in FIG. 1, the energy received by the first wafer during the stabilization of the temperature distribution in the process chamber is E ₀ , and the energy received by the second wafer during the normal processing is E ₀ . _2. Assuming that the energy received by the _first wafer during normal processing is E ₁ and the energy received by the n-th wafer during normal processing is E _n , the energy between these energy values is approximately , The following relationship is established. E ₀ > E ₁ = E ₂ = E _n On the other hand, as shown in FIG. 2, after the first wafer is used for stabilizing the temperature distribution in the process chamber,
Subsequently, when normal processing of the first wafer is started as it is, the relationship between the above energy values is roughly as follows. By applying the wafer-by-wafer processing method according to the present invention such that E ₁ > E ₂ = E _n or more, the temperature in the process chamber before setting each wafer during regular processing is set. As a result, the distribution and the thermal history received by each wafer during the processing are the same, so that there is no need to incorporate a first dummy wafer or dispose of the first wafer as a nonstandard product. By applying the single wafer processing method according to the present invention, a dummy wafer or the like can be removed from a single-wafer semiconductor manufacturing apparatus when the apparatus is started up or restarted after a temporary stop. It is possible to process all wafers as regular wafers without using them. As a result, it is effective in improving the production efficiency of the device or the yield.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a model diagram showing thermal energy received by a wafer set in a process chamber when a single wafer processing method of the present invention is applied. FIG. 2 is a model diagram showing thermal energy received by a wafer set in a process chamber when a conventional single wafer processing method of a wafer is applied. FIG. 3 is a plan view showing an outline of a single-wafer type semiconductor manufacturing apparatus. FIG. 4 is a sectional view of an AA portion of the single-wafer type semiconductor manufacturing apparatus of FIG. [Description of Signs] 1 ... Transfer chamber, 2 ... Transport robot, 3, 4 ... Cassette chamber, 5, 6 ... Process chamber, 30 ... Wafer, 33 ... Cassette lifter, 34 ... cassette, 37 ... control device, 4
0 ... wafer, 41 ... susceptor, 43 ... infrared lamp, 45 ... a quartz glass window, 46 ... temperature detectors, E _n ... n-th wafer in the process chamber Energy received during processing.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuo Kashiwagi 2068-3 Ooka, Numazu City, Shizuoka Prefecture Toshiba Machine Mytec Numazunai (56) References JP-A-1-236616 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/02 H01L 21/205 H01L 21/68

Claims (1)

(1) A method of processing a wafer in a single-wafer type semiconductor processing apparatus for processing a wafer under a heating atmosphere in a reaction chamber, wherein the processing is started or temporarily stopped. At the later restart, the first wafer is set in the reaction chamber, and after the temperature distribution in the reaction chamber is stabilized, the first wafer is removed from the reaction chamber without processing the first wafer, and the second and subsequent wafers are removed. Wafers are sequentially set in the reaction chamber and the processing is performed. For the first wafer extracted earlier, the processing is performed by interrupting the sequence between the processing of the second and subsequent wafers. A single wafer processing method for a wafer.