JPS5933251B2 - Plasma vapor phase processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in plasma vapor phase processing equipment, such as plasma CVD (chemical vapor deposition) equipment.

Since the plasma CVD method has the advantage of being able to form a CVD film at a relatively low temperature, it has recently been applied to the formation of passivation films for semiconductor devices.

A conventional apparatus used for forming a passivation film by the plasma CVD method, as shown in FIG. , e.g. SiH4+PH3+O2
Plasma is generated by applying a high frequency voltage to electrodes 1 and 2 in a mixed atmosphere of It is becoming.

In such a conventional plasma CVD apparatus, the plasma strength is not uniform between the electrodes, and as shown by the dotted line 6 in Figure 1, the plasma strength differs between the center and the periphery. Non-uniformity occurs in the thickness of the CVD film formed on the sample above 2, resulting in a decrease in the yield of semiconductor device manufacturing.

15 An object of the present invention is to provide a plasma vapor phase processing apparatus capable of producing a uniform plasma CVD film and performing uniform plasma etching.

In one embodiment of the present invention, one electrode facing the sample is divided into a plurality of parts and made movable, so that the distance between each electrode and the sample described above can be adjusted as desired. That is, in the present invention, based on the fact that the intensity of the plasma generated between the electrodes can be changed depending on the distance between the electrodes, the electrodes are divided into a plurality of parts and made movable. By adjusting the distribution, the intensity of the plasma generated between the electrodes can be controlled to be uniform at each location. An embodiment of the present invention will be described below with reference to FIG.

In FIG. 2, the same portions of 30 minutes as in FIG. 1 are indicated by the same reference numerals. The other movable electrodes 7, 8, 9, 10, and 11, which are divided into a plurality of parts, are provided opposite to the semiconductor wafers 3, 4, and 5 placed on the electrode 1, and each electrode is slightly The spacing is different from 1.

35, the electrode spacing distribution is the dotted line indicating the intensity of plasma generated when a high frequency voltage is applied between electrode 1 and electrodes T to 11 while introducing a reactive gas, for example, a mixed gas of SiH4 + PH3 + O2 between the opposing electrodes. As shown at 6, the positions between the electrodes are set in advance so that they are very uniform. By doing so, it becomes possible to deposit phosphorus glass films of approximately the same thickness on the semiconductor wafers 1, 3, 4, and 5 as the plasma gas reaction progresses. In carrying out the present invention, the number of electrodes to be divided into a plurality of parts is determined as appropriate based on the uniformity of the deposited film and the difficulty in operating the individual divided electrodes. Figure 3 shows
A holding structure for the movable electrode 7 is representatively shown as an example of the structure of the subdivided movable electrodes 7 to 11.

A conductive rod 7a attached to the movable electrode 7 is arranged so as to be movable up and down within the Persian. That is, an insulating holding plate 21 is fixed to the Persian wall 20 with a set screw 22, and a nut 24 fitted and fixed to the conductive rod 7a is screwed onto the outer peripheral surface of the rod surrounding portion 21a of the holding plate 21. There is. Note that 23 and 25 are sealings. According to such a structure, the vertical position of the electrode 7 can be finely adjusted by rotating and driving the nut 24 as necessary.
Can be set. By using the above-mentioned apparatus of the present invention, even if a passivation film is deposited on several dozen semiconductor wafers at once, the passivation film can be applied to each wafer with approximately the same thickness, resulting in improved yield. can be significantly increased. Note that the concept of the present invention can also be applied to a plasma etching apparatus.

[Brief explanation of drawings]

FIG. 1 is a sectional view illustrating an electrode section of a known plasma CVD apparatus, FIG. 2 is a sectional view illustrating an electrode section of a plasma CD apparatus of the present invention, and FIG. 3 is a sectional view showing a concrete structure of a movable electrode. It is a diagram. 1, 2... Electrode, 3, 4, 5... Semiconductor wafer,
6...Blasma intensity distribution, 7, 8, 9, 10, 11.
...Subdivided movable electrode.

Claims (1)

[Claims] 1. A sample is placed or secured on one of a pair of electrodes facing each other, and a high frequency voltage is applied to the pair of electrodes in a reactive gas atmosphere to generate plasma gas between the electrodes and cause the plasma gas to react. In a plasma vapor phase processing apparatus which deposits a desired thin film on the sample or performs vapor phase etching by using a method, at least one of the pair of electrodes is divided into a plurality of electrodes and made movable. A plasma vapor phase processing apparatus characterized in that the interval can be adjusted.