Patent Application
20130224965
This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2012-044803, filed on Feb. 29, 2012, the entire contents of which are incorporated herein by reference.
Embodiments described herein relates generally to a semiconductor manufacturing apparatus and a manufacturing method of semiconductor device.
As the semiconductor devices are being made finer and finer, in the manufacturing process, the technology of using metal materials as the wiring pattern and contacts on the semiconductor wafer as the workpiece for processing is becoming more and more important. Examples of the normally used metal materials include W (tungsten), WSi (tungsten silicide), Ti (titanium), TiN (titanium nitride), TiSi (titanium. silicide), Cu (copper), Ta2O5 (tantalum oxide), etc. The metals are deposited to form thin films.
Among the above-listed types of metals and metal compounds, the tungsten film is used more frequently since it has a low resistivity and a lower temperature for attaching the film. The tungsten film can be formed from WF6 (tungsten hexafluoride) used as the feed gas by reducing the feed gas using hydrogen, silane, dichlorosilane, etc.
When the tungsten film is to be formed on a substrate, if the tungsten film is directly formed on the substrate, the initial film is formed as a tungsten film including micro-crystals, so that the tungsten film formed on the initial film is also composed of grains with a small grain size, and hence the resistance rises. In order to solve the problem, one may use the following scheme: an amorphous layer is formed as the underlying layer and, on the amorphous layer, the tungsten film is formed so that it is possible to forma tungsten film with a large grain size and hence a low resistance.
In general, according to one embodiment, the semiconductor manufacturing apparatus can form a metal film; it includes a processing chamber that can carry out the processing of a substrate set in it, a gas feeding part that feeds the feed gas of the metal film and a plasma generating gas into the processing chamber, a plasma generating part that generates the plasma of the plasma generating gas, and a bias generating part that causes the ions generated by the plasma generating part to impact on the substrate.
There is provided a semiconductor manufacturing apparatus that can form a tungsten film with a low resistance and without restraint by the material of the underlying film, as well as a manufacturing method of a semiconductor device having the tungsten film.
In the following, Embodiment 1 will be explained with reference to figures.
In addition, the shower head part 3 may also have a structure wherein one or plural diffusing plates, each having plural diffusing holes, are arranged inside the shower head part so as to advance diffusion of the gas introduced therein. The shower head part 3 is connected with an RF power supply 5, so that it can be used as the upper electrode for generating plasma in the processing space.
In the processing chamber 2, a lower electrode 6 that can carry wafer W on it is arranged, formed from the bottom portion of the processing chamber. In addition to carrying the wafer W on it for film formation treatment, the lower electrode 6 also works as an electrode applied with a bias when the plasma processing of the wafer W is carried out. Below the lower electrode 6, a plural, for example, three, lifter pins (not shown in the figure) are arranged. As the lifter pins are driven to move up/down, the wafer W can be raised. Just as the shower head part 3, the lower electrode 6 is also connected with the RF power supply 5.
A gas exhausting port 7 is arranged in the peripheral edge of the bottom of the processing chamber 2. This gas exhausting port 7 is connected with a gas exhausting channel 8 connected to a vacuum pump not shown in the figure so that the interior of the processing chamber 2 can be evacuated to a certain vacuum level. Also, on the side wall of the processing chamber 2, a gate valve 9 is arranged so that it can be opened/closed when the wafer W is to be carried in/out.
As shown in
First of all, the manufacturing method of a semiconductor device using the semiconductor manufacturing apparatus of Embodiment 1 will be explained. The gate valve 9 arranged on the side wall of the processing chamber 2 is opened, and wafer W is carried into the processing chamber 2 by a transporting arm not shown in the figure. The lifter pins are then raised to transfer the wafer W to the side of the lifter pins. The lifter pins are then lowered so that the wafer W is carried on the lower electrode 6.
Next, Ar gas is fed into the processing chamber 2, and plasma is generated in the processing chamber 2 (S2). As shown in
Next, as shown in
In the following, Embodiment 2 will be explained with reference to figures. Different from the semiconductor manufacturing apparatus in Embodiment 1 that has a means for generating plasma in the film forming chamber, in Embodiment 2, a semiconductor manufacturing apparatus having an independent plasma processing chamber separately arranged in the same apparatus will be explained.
In the above, a multi-chamber type of film formation apparatus having two plasma processing chambers and two film forming chambers has been presented as an example. However, the present disclosure is not limited to this configuration, and the numbers of chambers may be selected appropriately.
Inside the transporting chamber 31, a transporting device 37 is arranged for transporting the wafer W into/out from the chamber. A load lock 38 is arranged between each loading port 32 and the transporting chamber 31.
First of all, the manufacturing method of a semiconductor device using the semiconductor manufacturing apparatus of Embodiment 2 as discussed above will be explained. In order to facilitate explanation, a discussion will be conducted on the formation of tungsten or some other metal film in both the first film forming chamber 35 and the second film forming chamber 36.
First of all, the wafer W to be used in the formation of a metal film is fed to the loading port 32 from the state of accommodation wherein 25 wafers are accommodated as 1 lot in a hoop. The wafer W fed to the loading port 32 is picked up by the transporting device 37 via the load lock 38, then it is transported to the first film forming chamber 35 or the second film forming chamber 36.
The feed gas of the metal film is then fed into the film forming chamber to form a metal film on the wafer W. In this case, the metal film formed on the wafer W is the initial film with a small grain size. After the end of the film forming processing of the initial film, the wafer W is picked up from within the film forming chamber by the transporting device 37, and is transported to the plasma processing chamber. In this case, it may be transported to either the first plasma processing chamber 33 or the second plasma processing chamber 34. It is possible to select the appropriate chamber while plural wafers W can be processed at a high efficiency.
For the wafer W transported into the plasma processing chamber, as the Ar ions generated in the Ar plasma impact it, an amorphous layer is formed in the upper layer of the initial film. The wafer W is then transported from the plasma processing chamber and is transported again to the film forming chamber by the transporting device 37. Since an amorphous layer has been formed in the upper layer of the initial film of the wafer W transported into the film forming chamber again, when a metal film is formed on the amorphous layer, it is possible to form it as a low resistance film with a large grain size.
After formation of the low resistance film with a large grain size, the wafer W is picked up by the transporting device 37 and is transported from the film forming chamber. The wafer W transported from the cooling chamber is transported via the load lock 38 to the hoop set in the loading port 32.
As explained above, according to the present embodiment, a plasma processing chamber is arranged as a separate chamber in the metal film forming apparatus, so that an amorphous layer can be easily formed by simply transporting the wafer between the chambers after formation of the initial film, so it is possible to form a metal film as a low resistance with a large grain size on the amorphous layer.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions. For example, upon forming the amorphous layer, it may be possible to form the plasma by using gas other than the Ar gas, and it is possible to use other materials as the initial film.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-044803 | Feb 2012 | JP | national |
