JP3792473B2 - Method for forming semiconductor thin film - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to an apparatus for forming a semiconductor thin film by plasma chemical reaction.
[0002]
[Prior art]
An apparatus for forming a semiconductor thin film by plasma chemical reaction includes a pair of electrodes for forming plasma in a reaction chamber, a substrate is held on one of the pair of electrodes, and a reaction gas is supplied from a reaction gas outlet provided on the other electrode. This is an apparatus for forming an amorphous silicon thin film or the like on a substrate by decomposing a reaction gas supplied from a reaction gas ejection port using plasma formed between a pair of electrodes.
[0003]
[Problems to be solved by the invention]
By the way, the reaction gas outlets provided in the electrode are arranged uniformly on the electrode surface in order to improve the flow of the reaction gas in the reaction chamber and to make the formed thin film uniform. When the process is performed for a long time, a formed film accumulates at the reactive gas outlet and causes clogging.
[0004]
When the reactive gas jet port is clogged, a uniform flow of reactive gas cannot be obtained, and the uniformity of the formed film is impaired.
[0005]
For this reason, in order to eliminate clogging of the reactive gas ejection port, it is necessary to periodically perform maintenance such as electrode cleaning and electrode replacement.
[0006]
However, if this maintenance is frequently performed, the production line is stopped during that time, so that there is a problem that the production cost increases accordingly.
[0007]
Therefore, the present invention is intended to make it possible to form a uniform film for a long time by increasing the maintenance period.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention provides a plurality of sets of a plurality of reactive gas outlets on the electrode, and the plurality of sets of reactive gas outlets are switched for each set by the outlet shielding means. It was made to open.
[0009]
Thus, if a plurality of sets of reactive gas jets are provided on the electrode and the reactive gas jets are used by switching for each set, the maintenance cycle can be lengthened by the number of sets. For example, when two sets of reactive gas outlets are provided and the first reactive gas outlet is clogged, the first reactive gas outlet is shielded by the outlet shielding means, By opening the reaction gas outlet, at least the maintenance cycle can be doubled.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a semiconductor thin film forming apparatus according to the present invention will be described with reference to the drawings.
[0011]
FIG. 1 shows a schematic configuration of a semiconductor thin film forming apparatus.
This semiconductor thin film forming apparatus includes a chamber 3 constituting a reaction chamber 2 for forming a semiconductor thin film such as an amorphous silicon thin film on a substrate 1 such as glass quartz. The chamber 3 is provided with a carry-in port 4 and a carry-out port 5 for loading and unloading the substrate 1 on the side wall, and an exhaust port 6 on the bottom wall.
[0012]
A pair of the lower electrode 7 and the upper electrode 8 are installed in the chamber 3 so as to face each other vertically.
[0013]
The lower electrode 7 is supported by a support shaft 10 slidably inserted into the bottom wall of the chamber 3 via an insulator 9 so as to move up and down and rotate. The substrate 1 is placed on the upper surface of the lower electrode 7. It has become so.
[0014]
The upper electrode 8 is suspended by a support shaft 12 inserted through an insulator 11 on the top wall of the chamber 3 and connected to a high frequency power source 13.
[0015]
A gas supply path 14 is provided inside the upper electrode 8 and the support shaft 12. On the lower surface of the upper electrode 8, a large number of reactive gas jets 15 are provided radially from the center so that the reactive gas blows out toward the substrate 1. As shown in FIG. The two reaction gas jets 15 are formed side by side at positions shifted to the left and right.
[0016]
The diameter of each reactive gas outlet 15 is about 1 mm. Moreover, the space | interval of the right and left in the reactive gas jet nozzle 15 for every group is formed about 50-150 mm.
[0017]
Inside the lower surface of the upper electrode 8, there is provided jet outlet shielding means 16 that shields all of the reaction gas jets 15 of one set and opens the reaction gas jets 15 of the other set. The shielding means 16 allows the reactive gas outlet 15 for each group to be switched between an open state and a shielded state.
[0018]
As shown in FIG. 3, the jet port shielding means 16 includes a plurality of shield plates 17 provided at predetermined intervals so as to block each set of reaction gas jet ports 15 arranged in the vertical direction, and the plurality of shield plates. It comprises a drive mechanism 18 that moves the plate 17 in the left-right direction to switch the reactive gas outlet 15 for each group between an open state and a shielded state. The drive mechanism 18 includes a crank rod 19 drawn out of the chamber 3 and a connecting rod 20 that connects the crank rod 19 and the shielding plate 17 in the upper electrode 8, and rotates the crank rod 19 from the outside of the chamber 3. By doing so, the shielding plate 17 can be moved left and right within the upper electrode 8.
[0019]
The contact surface between the shielding plate 17 and the lower surface of the upper electrode 8 is preferably subjected to a fluororesin coating treatment or the like in order to improve sealing performance and slipperiness.
[0020]
As described above, the semiconductor thin film forming apparatus shown in FIG. 1 has two sets of reaction gas jets 15, and the two sets of reaction gas jets 15 are switched and opened for each set by the jet port shielding means 16. Can be made.
[0021]
Therefore, when it is time to clog the first set of reactive gas outlets 15, the crank rod 19 is rotated to shield the first set of reactive gas outlets 15 by the shielding plate 17, and the second set of reactive gas. By opening the spout 15, at least the maintenance cycle can be doubled.
[0022]
In the above-described embodiment, the drive mechanism 18 for switching the reactive gas outlet 15 for each group between the open state and the shield state is configured by the crank rod 19 and the connecting rod 20 drawn out of the chamber 3, but the drive mechanism 18 is not limited to this, but may be another mechanism such as a cam mechanism.
[0023]
【The invention's effect】
As described above, the semiconductor thin film forming apparatus according to the present invention is provided with a plurality of sets of reaction gas jets on the electrode and can be used by switching the reaction gas jets for each set. The maintenance cycle can be lengthened by the number of outlet groups, and there is an effect that a uniform film can be formed over a long period of time.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of a semiconductor thin film forming apparatus according to the present invention. FIG. 2 is a plan view of a lower surface of an electrode provided with two sets of reactive gas ejection ports. And a plan view showing the relationship between the shielding plate and the drive mechanism, (b) is a side view of (a)
DESCRIPTION OF SYMBOLS 1 Substrate 2 Reaction chamber 3 Chamber 4 Carry-in port 5 Carry-out port 6 Exhaust port 7 Lower electrode 8 Upper electrode 9 Insulator 10 Support shaft 11 Insulator 12 Support shaft 13 High-frequency power supply 14 Gas supply path 15 Reactive gas jet port 16 Jet port shielding Means 17 Shield plate 18 Drive mechanism 19 Crank rod 20 Connecting rod

Claims (1)

In a method of forming a semiconductor thin film using a semiconductor thin film forming apparatus in which a plurality of sets of a plurality of reaction gas jets are formed on one of a pair of electrodes, one set of the reaction gas jets is used among the plurality of sets. A method of forming a semiconductor thin film, wherein the semiconductor thin film is formed, and the semiconductor thin film is formed by switching to another set of the reactive gas jets when the one set of reactive gas jets is clogged. .

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