JPS60167318A - Photo applied-semiconductor manufacturing device - Google Patents

Abstract

PURPOSE:To contrive to enhance work efficiency of a photo applied semiconductor manufacturing device by a method wherein at least two reaction chambers are provided in a reaction cell, the above-mentioned both reaction chambers are used alternately, and the light incident window of the reaction chamber not being used is purified. CONSTITUTION:The inside of a reaction cell main body 6 is separated into a first reaction chamber 11a and a second reaction chamber 11b according to a sluice valve 10. A wafer 3 to be processed is accommodated in the first reaction chamber 11a at first, and silicon is deposited on the wafer 3 to be processed according to a photo CVD reaction. Si is deposited also on a light incident window 7a for the degree of about 10min to reduce optical permeability, and when the reaction becomes hard to be generated, the sluice valve 10 is opened, and after the wafer 3 to be processed is transferred into the second reaction chamber 11b, deposition of Si onto the wafer 3 to be processed is continued similarly to the case at the first reaction chamber 11a. Then supply of SiH4 gas to the first reaction chamber 11a is stopped, carbon tetrafluoride gas is introduced, a high-frequency voltage is applied between electrodes 12a to generate plasma, and Si deposited to be adhered to the light incident window 7a is removed according to plasma etching.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to improvements in optical semiconductor manufacturing equipment.

[Prior art]

Below, we will discuss optical applications (3VD) that use light energy such as laser light and ultraviolet light.
The explanation will be given using chemical vapor deposition (CVD) equipment as an example. When manufacturing semiconductor integrated circuit devices, OVD is used for depositing an insulating film between two polycrystalline silicon layers of three MOI elements, and a non-sipation film. It is an important technique used. Conventionally, OVD mainly heated a reactive gas to cause a chemical reaction, but with the miniaturization of semiconductor devices, shallow junctions have become thinner.
low-temperature processing is desired due to the need for steeper impurity profiles to speed up operation, as well as the need to remove constraints on process order due to the use of multilayer interconnects and the prevention of process-induced defects. It is rare. Plasma OVD technology is currently being put into practical use as a technology that follows this trend. Recently, a method that uses light energy such as laser light or ultraviolet rays as an energy source for low-temperature OVD has attracted attention, and this method can be used to perform optical-applied OVD.
A prototype of the device is being manufactured.

FIGS. 1 and 2 are schematic cross-sectional views showing conventional reaction tube type and reaction cell type optical CVD apparatuses, respectively. In Figures 1 and 2, (1) is ultraviolet (UV)
(2) is a reaction tube made of a material that transmits light; (3) is a wafer to be processed; (4) is a chemical reaction lamp that emits radiation;
) is a susceptor on which the wafer to be processed (3) is placed, (5
) is 71 auxiliary heating infrared lamp, (6
) is the reaction cell body, (7) is a light entrance window made of a light-transmitting material, (8) is a reactive gas inlet, and (9) is a reactive gas outlet. The reaction gas is introduced from the reaction gas inlet (8) as shown by the arrow, and is discharged from the reaction gas outlet (9) as shown by the arrow 0.

However, in conventional devices such as those mentioned above.

The solid matter produced by the reaction coats the wall of the reaction tube (2).

It adheres to the light entrance window (7) of the reaction cell, blocking the transmission of light, making it difficult for the reaction to proceed, and causing the thickness of the deposited film on the wafer to become saturated over time, as well as the deposition conditions for each operation and the reproduction of product wafers. Sexuality may be impaired.

[Summary of the invention]

This invention has been made in view of the above points, and provides at least two reaction chambers in a reaction cell so that reaction product solids adhering to the light entrance window of each reaction chamber can be easily removed. In addition, by alternately using both of the reaction chambers and cleaning the light entrance window of the reaction chamber that is not in use, an optical semiconductor manufacturing apparatus is provided which is highly efficient in operation.

[Embodiments of the invention]

FIG. 3 is a schematic sectional view showing the configuration of an embodiment of the present invention, in which the interior of the reaction cell body (6) is divided into a first reaction chamber (lla) and a second reaction chamber (xlb) by a gate valve QO. The first reaction chamber (lla) has a light entrance window (7a).
A reaction gas inlet (8a) and a reaction gas outlet (9a) are provided in the second reaction chamber (1xb).
b).

A reaction gas inlet (sb) and a reaction gas outlet (9a) are provided, and the operation of each reaction chamber is the same as in the conventional example shown in FIG. , (12a) and (12b) are the first reaction chamber (lla) and the second reaction chamber (lxb), respectively.
The wafer (3) to be processed is moved into the first reaction chamber (lla) through a stump, which is an electrode for generating plasma.
monosilane (S) from the reaction gas inlet (8a).
ta4) Gas is introduced, and ultraviolet light is irradiated through the light incidence window (7a) as indicated by the dashed arrow UV to deposit silicon (Sl) on the wafer to be processed (3). Sl is also deposited on the light entrance window (7a) for about 10 minutes, reducing the light transmittance and making it difficult for a reaction to occur.Then, the gate valve ui is opened and the wafer to be processed (3) is transferred to the second reaction chamber ( 11b),
After closing the gate valve Q0, the deposition of Si on the workpiece wafer (3) is continued in the same manner as in the first reaction chamber (lla). At this time, the first reaction chamber (ll
Stop the supply of 14 gas at 81 to a), and add carbon tetrafluoride (
CF4) gas is introduced, a high frequency voltage is applied between the electrodes (12a) to generate plasma, and the Si deposited on the light incident window C'7a) is removed by plasma etching. This removal is completed in about 10 seconds.Next, if the reaction rate in the second reaction chamber (11b) decreases, the workpiece wafer (3) is transferred to the first reaction chamber (11b) in the same manner as described above. lla
) to continue the deposition of Sl, and then transferred to the second reaction chamber (1
The Sl deposited on the light entrance window ('7b) of 1b) is removed. Thereafter, this process is repeated to deposit Si on the wafer to be processed (3) until the desired film thickness is reached.In this way,
By constantly irradiating light through a clean light entrance window, it is possible to deposit Sl almost continuously and efficiently.

In the upper part, the case of vapor phase deposition of 81 was explained, but other materials such as silicon nitride (5L3N4) * silicon dioxide (S10□) may also be used. The present invention can be applied to optical semiconductor devices in general, such as vapor phase etching devices and vapor phase doping devices. Furthermore, the movement of wafers between reaction chambers can be automated.

〔Effect of the invention〕

As explained above, in the optical semiconductor manufacturing apparatus according to the present invention, the reaction cell is divided into a plurality of reaction chambers each having a light entrance window and a means for cleaning the inner surface of the light entrance window,
A semiconductor wafer to be processed is subjected to an optical vapor phase chemical reaction in the first reaction chamber, and when the light transmittance of the light entrance window decreases, the semiconductor wafer to be processed is transferred to a second reaction chamber and subjected to an optical vapor phase chemical reaction. Since the inner surface of the light entrance window in the first reaction chamber can be cleaned while the reaction continues, extremely efficient operation is possible.

[Brief explanation of the drawing]

1 and 2 are schematic sectional views showing the configuration of conventional reaction tube type and reaction cell type optical OVD devices, respectively, and FIG. 3 is a schematic sectional view showing the configuration of an embodiment of the present invention. It is. In the figure, (3) is the semiconductor wafer to be processed, (6) is the reaction cell body, (7a) and (7b) are the light entrance windows, 00 is the gate valve, (lla) and (llb) are the reaction chambers, (12a)
) and (12b) are electrodes for plasma generation. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Masuo Oiwa Figure 1 Figure 2 Figure 3 Procedural amendment (voluntary) 1. Indication of the case Japanese Patent Application No. 59-023249 2. Title of the invention Optical semiconductor manufacturing equipment 3. Case of the person making the amendment To Hitoshi Katayama, Representative of the Patent Applicant, Section 4, Agent 4, Column 5 of Detailed Description of the Invention of the Specification Subject to Amendment, and the amended Chopstick Specification are amended as follows.

Claims (4)

[Claims] (1) It has a light entrance window covered with a transparent material, and uses the energy of light incident from outside through this light entrance window to perform a gas phase chemical reaction on the semiconductor wafer to be processed inside. In a device equipped with a reaction cell, the reaction cell is divided into a plurality of reaction chambers each having a light entrance window and means for cleaning the inner surface of the light entrance window, and the first of these reaction chambers is When the semiconductor wafer to be processed is subjected to the vapor phase chemical reaction in the reaction chamber of 71 is transferred to a second reaction chamber to continue the gas phase chemical reaction, and in the first reaction chamber, the inner surface of the light entrance window of the reaction chamber can be cleaned by the cleaning means. Optical semiconductor manufacturing equipment characterized by: (2) The optical semiconductor device according to claim 1, further comprising a device for generating gas plasma within the reaction chamber as means for cleaning the inner surface of the light entrance window. (3) The optical semiconductor manufacturing apparatus according to claim 1 or 2, characterized in that the movement of the semiconductor wafer to be processed between reaction chambers is automated. (4) Optical semiconductor manufacturing according to any one of claims 1 to 3, characterized in that the vapor phase chemical reaction using light energy is a photo-applied chemical vapor deposition reaction. Device.