Abstract:
The present invention relates to a rapid thermal processing tool comprises a housing, a chamber formed inside the housing is able to contain an object for a rapid thermal process, a valve formed on the head of the housing, a transit ring formed inside the chamber for inputting and outputting the object in and out of the chamber from the valve, a front exhaust valve formed on the head of the housing and adjacent to the valve, a delivery valve formed inside the chamber for delivering a vapor into the chamber, and a back exhaust valve formed on the back of the housing.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a rapid thermal processing tool, and more particularly, to a rapid thermal processing tool having a front exhaust valve.  
         [0003]     2. Description of the Prior Art  
         [0004]     The rapid thermal processing tool has become more important in recent years due to the development of larger scale, high density single-wafer processing. This trend is cause by the rapid thermal processing tool&#39;s flexibility in product production and the stable manufacture. The traditional furnace has high thermal mass and low uniform, and therefore does not apply in the high density and single-wafer manufacturing process. It is succeeded by the rapid thermal processing tool. Additionally, the rapid thermal processing tool has a low thermal budget.  
         [0005]     The rapid thermal processing tool works best for rapid thermal oxidation utilized to grow the thin-dielectric, rapid thermal CVD to handle the amorphous silicon, polysilicon tungsten, silicon dioxide and silicon nitride, ion implantation, crystal recombination and stress concentration smooth after silicidation, reflow of borophospho-silicate glass, and rapid thermal annealing of nitridation.  
         [0006]     Recently, most rapid thermal processing tools have an exhaust valve, however, the exhaust valve is located far from the valve and purges the chamber by the delivery valve delivers nitrogen etc., that wastes time and purge air. Please refer to the  FIG. 1 .  FIG. 1  is schematic diagram of the conventional thermal processing tool structure. The rapid thermal processing tool  100  has a housing enclosure  124  to cover the inner chamber  118  and the valve  102 . When the wafer  116  enters the rapid thermal processing tool  100  (e.g., for the thermal processing process), the valve  102  must open allowing the wafer  116  to enter. In general, the valve  102  opens after the exhaust valve  106  closes. This is necessary because if the exhaust valve  106  is open at this time then too much air will enter into the chamber  118 . The air will affect the rapid thermal processing tool&#39;s processing of the wafer. The outcome will include: unnecessary impurities in the product and a decrease in the product yield. It is for these reasons that the exhaust valve  106  must close when the valve  102  opens. After the wafer  116  has entered the chamber  118 , the exhaust valve  106  will open.  
         [0007]     When the wafer  116  is put upon the quartz pin  114 , the guide ring  112  will deliver the wafer  116  to the fit position. At this point, the delivery valve  104  will put much of the vapor like the nitrogen and argon into the chamber  118 . The oxygen and impurities will be purged in the chamber  118 . The nitrogen and argon are controlled by a control valve (not shown) to control the flow rate and the chamber  118  is retained the constant pressure by the exhaust valve  106 . Otherwise, the chamber  118  has the oxygen sensor  122  to measure the oxygen concentration in the chamber  118  accurately, and when the oxygen concentration decreases to acceptable concentration, the delivery valve  104  will stop pouring nitrogen and argon and the exhaust valve  106  will close. Next, the wafer is heated rapidly by the lamp  108  for RTO, RT CVD and RTA etc. The pyrometer  120  of the chamber  118  inspects the temperature. After finishing the process, the wafer  116  outputs form the chamber  118 .  
         [0008]     Please refer to  FIG. 2 .  FIG. 2  is a schematic diagram of the oxygen concentration of the chamber  118  after the valve  102  opens. When the valve  102  is open, the oxygen concentration of the chamber  118  will rise up to D 1  in period T 1 . The rapid thermal processing tool  100  will purge the oxygen (i.e., exhaust the oxygen) that is in the chamber  118  by the utilization of the delivery valve  104  and the exhaust valve  106 . After T 3 , the chamber&#39;s  118  oxygen concentration will decrease to an acceptable concentration level for starting the process.  
         [0009]     In the other words, the air management system of the conventional rapid thermal processing tool  100  exists the variations of high unnecessary air concentration in the chamber  118  and long retention period of unnecessary air, which wastes great nitrogen and argon to purge the oxygen in the chamber  118 . It wastes time and materials in the manufacture process and causes the unstable manufacture quality to affect product yield and yield rate. For this reason, it is importance to find a rapid thermal processing tool to solve the above-mentioned problems.  
       SUMMARY OF THE INVENTION  
       [0010]     The present invention relates to a rapid thermal processing tool, and more particularly, to a rapid thermal processing tool having a slit exhaust valve.  
         [0011]     According to the claimed invention, the rapid thermal processing tool comprises a housing, a chamber formed inside the house is able to contain an object for a rapid thermal process, a valve formed on the head of the housing, a transit ring formed inside the chamber for inputting and outputting the object into the chamber from the valve, a front exhaust valve formed on the head of the housing and adjacent to the valve, a delivery valve formed inside the chamber for delivering a vapor into the chamber, and a back exhaust valve formed on the back of the housing.  
         [0012]     The rapid thermal processing tool, according to the present invention, has a front exhaust valve adjacent to the valve itself to rapidly output the air as it exits form the valve and the delivery valve for injecting the nitrogen and argon. Therefore, the present invention resolves the defect of the air management system in the prior art by decreasing the time needed to purge the oxygen and inject the nitrogen and argon into the chamber.  
         [0013]     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  is a schematic diagram of the conventional thermal processing tool structure.  
         [0015]      FIG. 2  is a schematic diagram of the oxygen concentration level in the chamber after the valve opens.  
         [0016]      FIG. 3  is a schematic diagram of the rapid thermal processing tool structure according to the present invention.  
         [0017]      FIG. 4  is a schematic diagram showing the oxygen concentration level changing in the chamber after the valve opens.  
         [0018]      FIG. 5  is a schematic diagram of barrier layer manufacture. 
     
    
     DETAILED DESCRIPTION  
       [0019]     Please refer to  FIG. 3 .  FIG. 3  is a schematic diagram of the rapid thermal processing tool structure according to the present invention. The rapid thermal processing tool  200  according to the present invention has a housing enclosure  224  to cover the inner chamber  228 . The valve  202  is formed on the top of the housing enclosure  224 , the front exhaust valve  230  is formed adjacent to the valve  202  and the transit ring comprises the guide ring  212  and the quartz pin  214  inside the chamber  218 . When the object like the wafer  226  enters the rapid thermal processing tool  200  (e.g., for the thermal processing), the front exhaust valve  230  will open and the delivery valve  204  formed on the central bottom area of the chamber  218  will open at the same time. The delivery valve  204  purges vapor like nitrogen and argon to balance the pressure of the chamber  218 . Next, then the valve  202  will open allowing the wafer  226  into the chamber  218 .  
         [0020]     Because the front exhaust valve  230  is located adjacent to the valve  202 , the rapid thermal processing tool  200  reduces any disturbance flow caused by the opening of the valve  202 . In comparison to the conventional tool, the present invention will be capable of decreasing the time needed for the front exhaust valve  230  to exhaust air from the chamber  218 . The delivery valve  204  delivers nitrogen and argon into the chamber  218  such that air cannot enter the chamber  218  deeply. Because of the front exhaust valve  230  exhausts air out from the chamber  218  and the delivery valve  204  delivers nitrogen and argon into the chamber  218  that balances the pressure of the chamber  218 . The oxygen concentration in the chamber  218  of the present invention changes slightly.  
         [0021]     After the wafer  216  enters the chamber  218 , the valve  202  closes. The rapid thermal processing tool  200  closes the front exhaust valve  230  and opens the back exhaust valve  206  formed on the back of the housing enclosure  224 . At the same time, the delivery valve  204  continues purges nitrogen and argon and the wafer  216  is delivered into the fit position by the quartz pin  214  of the guide ring  212 . Next, the oxygen sensor  222  in the chamber  218  in the present invention inspects the oxygen concentration level of the rapid thermal processing tool  200 . When the concentration level is below the standard level, the nitrogen and argon input flow will cease and the back exhaust valve  206  will close. The air comes firstly into the chamber  218  is exhausted by the front exhaust valve  230 . Even, the present invention opens the delivery valve  204  and the back exhaust valve  206  in next process like the prior art, the oxygen concentration of the chamber  218  decreases quickly and the effect is better. Next, the wafer  216  will be heated rapidly by the lamp  208  for RTO, RT CVD, RTA, and so on. The pyrometer  220  in the chamber  218  will inspect the temperature change. Once this process is completed, the wafer  216  will be removed utilizing the valve  202  of the chamber  218 .  
         [0022]     Please note, the chamber  218  of the rapid thermal processing tool  200  is not a closed space. The space could exist by a combined upper wall and lower wall. And the cracks exist on the walls. The cracks could deliver air and replace the opens of the valve  230 ,  206  and  214 . Otherwise, the lamp  208  of the tool could select form one of the tungsten halogen lamp, arc lamp, resistive heater and the combination of them. The lamp  208  could be formed on the upper house or the lower house or both of them, it dependences on the need of the semiconductor process. Even the temperature and the purge air could be changed dependences on the process.  
         [0023]     Please refer to  FIG. 4 .  FIG. 4  is a schematic diagram of the oxygen concentration level in the chamber changes after the valve opens. When the valve  202  opens and the wafer  216  enters the chamber  218  through the guide ring  212 , the oxygen concentration in the chamber  218  will rise up to D 1  in period T 1 . Because of the front exhaust valve  230  of the rapid thermal processing tool  200  according to the present invention exhausts great air form the chamber  218  and the delivery valve  204  delivers purge air to decreases the disturbance flow, the oxygen comes into the chamber  218  will exhaust out during short T′ 2 . The time (T′ 1 +T′ 2 )of purging the oxygen in the chamber  218  in the present invention is shorter than the time (T 1 +T 2 +T 3  ) in the prior art. And the oxygen concentration D′ 1  in the present invention is lower than D 1  in the prior art.  
         [0024]     The ability of the rapid thermal processing tool of the present invention to exhaust the oxygen in the chamber make this tool applies for non-oxygen thin film deposition etc. in the semiconductor process. Please refer to  FIG. 5 .  FIG. 5  is a schematic diagram of a barrier layer manufacture. In the process of barrier layer manufacture, the barrier layer  504  is formed on the silicon oxide  502  by etching the contact holes on the dielectric silicon oxide  502  on the surface of the wafer  500 .Titanium is sputtered on the wafer  500  around the nitrogen, nitrides to TiN in high temperature. We also can use the responsive sputter process to form the barrier layer  504 , TiN on the surface of the wafer  500 . After finishing the barrier layer  504  on the wafer  500 , the wafer is inputs in the rapid thermal processing tool  200  for RTA. In the same way, the front exhaust valve  230  opens and the delivery valve  204  opens to delivery nitrogen and argon to balance the pressure in the chamber  218 . Next, the valve  202  opens and the wafer  500  inputs into the chamber  218  by the guide ring  212 . As the above-mentioned, the disturbance flow is exhausted by the front exhaust valve  208 , and the delivery valve  204  opens and the air can&#39;t come deeply in the chamber  218 . After the valve  202  closes, the front exhaust valve  230  closes and the back exhaust valve  206  formed on the back of the house  224  opens. When the oxygen sensor  222  inspects the concentration of the chamber  218  is fit, the lamp  208  will process the rapid thermal processing. The tungsten deposition and CMP etc. are known well by the prior art and no more description.  
         [0025]     Compared with the prior art, the rapid thermal processing tool, according to the present invention, has a front exhaust valve adjacent to the valve itself to rapidly output the air as it exits form the valve and a delivery valve for inputting the nitrogen and argon. Therefore, the present invention resolves the defect of the air management system in the prior art by decreasing the time needed to purge the oxygen and to introduce the nitrogen and argon in the chamber.  
         [0026]     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.