JPH02224221A - Manufacture of semiconductor device, substrate treatment apparatus and semiconductor device manufacturing apparatus - Google Patents

Abstract

PURPOSE:To obtain the proper surface of a functional thin film and improve the yield of a semiconductor device by a method wherein a substrate is conveyed under the depressurized atmosphere of gas which has no influence upon the thin film surface, for instance in the depressurized atmosphere of rare gas after the functional thin film is formed. CONSTITUTION:Even if a substrate is conveyed to other processes 2a-2c for treatments after a film is formed, if the atmosphere of a substrate conveying path 3 is an atmosphere depressurized from the air, the unarmed hands of the substrate react with nitrogen and oxygen while the substrate passes through the substrate conveying path 3 and nitride and oxide are formed on the thin film surface. Therefore, even if functional films are successively formed in the other processes, a proper junction surface can not be formed in the boundary between the previously formed film and the film formed in the next process. If a depressurized rare gas atmosphere is employed as the atmosphere of a substrate conveying path 3, rare gas atmos are coupled with the uncoupled hand parts but no chemical reaction occurs. Therefore, the substrate can be subjected to the next process while the surface state is active. With this constitution, a treatment such as improvement of the junction surface which does not deteriorate the device characteristics can be performed and the device can be manufactured with a high yield.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method of continuously forming functional thin films in a method of manufacturing semiconductor devices, and particularly to optimization of thin film interfaces and improvement of yield of semiconductor devices. Regarding how to achieve this.

[Conventional technology]

The conventional apparatus, for example, as described in Japanese Patent Application Laid-Open No. 131513/1984, forms a functional thin film on a substrate and then transports the substrate to the next functional thin film forming chamber through a transport passage under reduced pressure in an atmospheric atmosphere. A method was taken.

[Problem that the invention sought to solve]

The above conventional techniques do not take into consideration the condition of the thin film surface after forming a thin film, especially a highly functional semiconductor film, or the atmosphere of the passageway through which the substrate is transported, and the manufactured semiconductor device does not meet the desired expectations. There was a problem that it did not show the expected function.

An object of the present invention is to improve the above-mentioned disadvantages.

[Means to solve the problem]

In order to achieve the above purpose, after forming the functional film, the substrate should not be exposed to the atmosphere, but should also not be exposed to the atmospheric atmosphere under reduced pressure or a nitrogen atmosphere, and should not be exposed to the next process. It was designed to do so. 7. In other words, after the functional thin film has been formed, the substrate is transported under a reduced pressure atmosphere of a gas that does not affect the thin film surface, such as a reduced pressure atmosphere of a rare gas or a reduced pressure atmosphere of a gas for subsequent processing. It is. Furthermore, in order to avoid the influence of the gas atmosphere in the processing chamber, at least one step of substrate processing is
Plasma is generated using electron cyclotron (hereinafter abbreviated as ECR) resonance, and a substrate is treated with the plasma.

[Effect]

There are many dangling bonds on the surface of the functional thin film immediately after formation. This dangling bond has high chemical reactivity, so for example,
Even if the film is immediately transported to a separate processing room and processed,
If the atmosphere in the substrate transport passageway is at reduced pressure, the dangling bonds will react with nitrogen and oxygen while passing through this passage, and nitrides and oxides will be formed on the thin film surface. . Therefore, even if functional films are successively formed in the next process, it is impossible to form an appropriate bonding surface at the interface with the previously formed film. Therefore, if the atmosphere in the substrate transport path is made into a reduced pressure atmosphere of rare gas, rare gas atoms will adhere to the dangling bonds, but no chemical reaction will occur, so the next treatment can be performed while the surface state 5 remains active. .

Instead of the rare gas atmosphere, a reduced pressure atmosphere of the gas used for the primary treatment may be used, since in this case, the dangling bonds are covered by atoms constituting the film to be formed next.

Good results can be obtained with the next film.

In addition, when processing a substrate using plasma, if the operating pressure during processing is high, the amount of adsorption of the gas species to be processed on the substrate in the processing chamber increases after processing, and as a result, the amount of gas species to be processed that is formed during the next processing increases. A problem arises in that the bonding surface with the membrane cannot be made properly. Therefore, the bonding surface can be made more suitable by performing plasma treatment using electron cyclotron resonance, which requires a lower operating pressure.

Furthermore, when a substrate is processed using plasma, a surface irradiated with plasma, for example, a substrate holder surface, is sputtered. Therefore, atoms of the material to be sputtered are incorporated into the substrate. Therefore, for example, when forming a silicon film,
If you try something like placing a silicon plate under the board,
The appropriateness of the joint surfaces described above will be further promoted.

(Example〕 The present invention will be explained below using examples.

Embodiment 1 FIG. 1 shows a cross section of the main parts of a plasma processing apparatus based on the present invention. The device is installed in sample chambers 1, 2, and 3 of sample chambers 1 and 3. Gas introduction pipes 4a, 4b, 4c for introducing gas into the plasma processing chambers 2a, 2b, 2c, the substrate transfer chamber 3, and the respective processing chambers
, 5a, 5b, 5c exhaust ports (not shown), RF power source 6. Upper RF group electrode.

Lower earth electrode 8. Gate valves 9, 10. Sample extraction chamber 11. It consists of a nozzle 12° for sending gas to the transfer chamber 3 and an exhaust port 13 of the transfer chamber 3. As a substrate 14, a laminated film of n-type silicon/non-doped silicon/nitride was continuously formed on a glass plate of 100 (nn) square. For formation, the sample chamber 1 or the sample 14 is transported to the first plasma processing chamber 2a by opening the gate valve 9, and the inside of the chamber 2a is placed in a 5×10”-2 (To
After exhausting to rr), ammonia,
NHs was introduced at 20 Cm n /win) and monosilane SiSiH45 (/win) was introduced from 5a to 1 (Torr).
Then, apply 300 (W) of RF from the RF power supply, and 7) I
, tmif, A Q 203 film-covered upper and lower electrodes 7
A silicon nitride film, SiN, was deposited by discharging between
), and sent to the plasma processing chamber 2b via the substrate transfer chamber 3 at a pressure of IX 10'-'' (Torr).Next, the inside of 2b was evacuated to 5X10-2 (Torr),
Next, 20% hydrogen, H2, is passed through the gas nozzles 4b and 5b.
(m Q /m1n), S i H4 is 5 (m
Amorphous silicon (iJl) was deposited on the SiN film at a pressure of 1 (Torr) and an RF energy of 300 (W). After deposition, 5 x 10-2 (T
It was evacuated to orr:l and sent to the plasma processing chamber 2c via the substrate transfer chamber 3. Next, 5X 10-2 (
Phosphine, PHa diluted to 5% with hydrogen through gas nozzles 4c and 5b.
20 (m Q /+++in), and S i H4
5 [m Q /min] was introduced to deposit a phosphorus-doped n-type silicon film (n layer) on the above-mentioned one layer. Next, the pressure inside 2c was reduced to 5×10 ”-” [Torr], and then the sample was sent into the sample extraction chamber 11 . During the above film formation, the atmosphere in the substrate transfer chamber was (A) a reduced pressure nitrogen atmosphere after introducing nitrogen N2 through a nozzle and then reduced pressure; (B) a reduced pressure after introducing helium and He through a nozzle. The formed film was subjected to elemental analysis by XPS in a rare gas atmosphere. In the case of (A), trace amounts of oxygen and hydrogen as well as nitrogen were detected between the i-layer and the n-layer, but in the case of (B), no nitrogen was detected.

Using the laminated films formed in cases (A) and (B) above, a transistor was formed through predetermined steps.
), the defective rate was 35%, but in (B)
In this case, it was 10% or less. The cause of the defect was due to a defective bond between the first layer and the n layer. Considering this in conjunction with the previous xPS analysis, in the case of (A), after the i-layer was formed, it passed through a substrate transport chamber with a nitrogen atmosphere, so the dangling bonds on the formation surface reacted with nitrogen, and a SiN film was formed on the surface. It can be seen that this is because the bonding with the upper n-layer cannot be achieved properly. On the other hand, as in case (B), when the substrate passes through a transfer chamber with a rare gas atmosphere, the rare gas adheres to the dangling bond, but the active surface is maintained because the rare gas does not react. It can be seen that a proper bonding surface was formed because the bonding surface was transferred to the next process.

Example 2 Instead of (B) above, the transfer chamber was placed in a reduced pressure state of hydrogen atmosphere (C), and a 1-transistor was manufactured in the same manner as above.

The defect rate was <10% or less, the same as in (B).

These results show that proper semiconductor processing can be performed when the atmosphere in the substrate transfer chamber is reduced to a rare gas atmosphere or a reduced pressure atmosphere similar to the type of gas used in the subsequent processing.

Example 3 FIG. 2 shows a cross-sectional view of a one-shot process according to the present invention. A feature of this device is that it uses electron cyclotron resonance (ECR) rather than RF discharge to generate plasma. In this device, the magnetic field coil 18 applies a magnetic field strength that satisfies the ECR conditions into the vacuum vessel, and after introducing gas, the μ-waves 16 are passed through the μ-wave source tube 17 to the μ-wave introduction window 2.
1, when introduced into the replasma generation chamber 19 (a"c), EC
Plasma is efficiently generated by R. Board holder 15
A holder made of quartz was used. When the plasma is introduced into the substrate processing chambers 20 (a to C) by magnetic lines of force 22 and reacted with the reaction gas, the substrate can be subjected to desired processing. Using this device, the μ-wave power was 300 (W) at the same gas flow rate as in the example.
The same laminated film was formed under the following conditions: the reaction pressure was 1 x 10'''' (Torrl), the pressure before and after the treatment was 1 x 10 Torr, and the transfer chamber was under reduced pressure of I x 1 O-5 (Torr) in a He atmosphere. A subsequent interface analysis revealed that in addition to a trace amount of oxygen at the interface between the i-layer and n-layer, hydrogen, which was detected in Example 1, was not detected.The failure rate of the transistor using this laminated film was 3. [%] or less.This is
It can be seen that this is because the reaction between the dangling bond immediately after treatment and the gas used was suppressed to a low level due to the low operating pressure of the ECR plasma, which enabled further optimization of the bonding surface.

Example 4 The oxygen detected at the interface between the i-layer and n-layer is as follows.

The cause is thought to be quartz sputtered when the substrate holder is irradiated with plasma. If oxygen is mixed in, it becomes difficult to form a proper bonding surface. To prevent this,
The same experiment as in Example 3 was conducted with a silicon plate placed on the substrate holder. As a result, the previously detected oxygen was
It was not detected in this experiment. Further, when transistors were manufactured and the defective rate was examined, the defective rate was 0.5% or less. This shows that if the surface to which plasma is irradiated is made of a material that does not affect the device, for example, silicon when forming a silicon film, processing in semiconductor manufacturing can be further optimized.

〔Effect of the invention〕

According to the present invention, in a continuous plasma processing method, it is possible to perform processing without degrading device characteristics, such as optimizing the bonding surface, so that it is possible to form a device with a high yield.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an RF plasma processing apparatus showing an embodiment of the present invention, and FIG. 2 is a sectional view of a plasma processing apparatus showing an embodiment of the invention. 2a, 2b, 2c...substrate processing chamber, 3...substrate transfer chamber, 7...upper RF electrode, 8...lower substrate installation electrode, 15...substrate holder, 16...microwave , 18
...Magnetic field coil, 19 a, 19 b, 19
c-plasma generation chamber, 20a, 20b,
20 c - processing chamber. Procedural amendment (method) Relationship between % formula % and the person/Iif'l who amends the semiconductor device manufacturing equipment Patent applicant and Haku+51L11 type association ll Date of Hitachi agent's amendment order May 30, 1999 (Shipping mortar)

Claims (1)

[Claims] 1. Semiconductor device manufacturing characterized in that after processing a substrate, subsequent processing is performed on the substrate without exposing the processed substrate to the air, a nitrogen atmosphere, or a reduced pressure atmosphere. Method. 2. An apparatus for continuously processing substrates, characterized in that the atmosphere in the path through which the substrates are transported is a gas atmosphere containing at least one type of gas used in the next processing, or a reduced pressure state of a rare gas atmosphere. A method for manufacturing a semiconductor device according to claim 1. 3. The semiconductor device manufacturing method according to claims 1 and 2, wherein the process includes continuous formation of a functional thin film. 4. The method of manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the process includes at least the step of forming an n-layer of silicon subsequent to the formation of the i-layer of silicon. 5. Claim 1, characterized in that in the above treatment, at least one treatment uses plasma generated using electron cyclotron resonance to treat the substrate.
5. A method for manufacturing a semiconductor device according to items 4 to 4. 6. Having at least a processing chamber for processing the substrate and a substrate transport path without exposing the substrate to the atmosphere, and continuously processing the substrate by moving the substrate between the processing chamber and the substrate transport path multiple times. What is claimed is: 1. A substrate processing apparatus characterized in that the atmosphere in a substrate transport path is a reduced pressure state of at least one type of gas used in subsequent processing or a rare gas atmosphere. 7. In the above-mentioned substrate processing, plasma is generated using electron cyclotron resonance, and the method is characterized in that it has at least one chamber capable of processing the substrate with the plasma. Substrate processing equipment. 8. (1) Forming an insulating layer, (2) Forming a semiconductor film, (3) Passing a substrate transport path under reduced pressure in a rare gas atmosphere.
In the three steps, (1)-(3)-(2)-(3)-(
A semiconductor device manufacturing method according to any one of claims 1 to 5, characterized in that a liquid crystal display is manufactured including at least the process steps in the order of 2). 9. The semiconductor device manufacturing apparatus according to claims 6 and 7, characterized in that a substance whose main component is the same as that of the formed film is placed on a surface that is exposed to the plasma. 10. The semiconductor according to claims 1 to 5, characterized in that when forming a silicon film using plasma, the substrate is placed on a silicon plate or a holder coated with silicon. Device manufacturing method.