JP2005209787A - Method of manufacturing semiconductor device and treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor device which reduces the variation of the thickness of the semiconductor layer of an SOI substrate. <P>SOLUTION: The method comprises (a) a step of preparing an SOI substrate 10A composed of the laminate of a support substrate 10, an insulation layer 12, and a semiconductor layer 14a; (b) a step of measuring the thickness of the semiconductor layer 14a; (c) a step of applying oxidation treatment to the SOI substrate 10A to form an oxidation film 16 above the semiconductor layer 14a; and (d) a step of removing the oxidation film 16. An oxidation treatment condition is determined based on the thickness of the semiconductor layer 14a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method of manufacturing a semiconductor device including an SOI substrate, and more particularly to a method of manufacturing a semiconductor device and a processing apparatus capable of manufacturing an SOI substrate that is a thin film and has a semiconductor layer with a uniform thickness.

In recent years, with the demand for lower power consumption and higher speed of integrated circuits, SOI (Silicon On Insulator) substrates have been used instead of bulk semiconductor substrates. The SOI substrate is a substrate in which a semiconductor layer is provided on an insulating layer, and a field effect transistor (FET) or the like can be provided on the semiconductor layer, for example. Field-effect transistors formed in a semiconductor layer of an SOI substrate can reduce parasitic capacitance such as junction capacitance and wiring capacitance, and can operate with low power consumption devices such as LSIs for portable information terminals and high-speed operation circuits such as high-speed CPUs. Application to is expected. In particular, a transistor in which the silicon layer in the channel region is all depleted has an advantage that the problem related to the substrate floating effect in the partially depleted transistor is reduced.
JP 2000-216366 A

  However, with further reduction in power consumption and speed in recent years, there is an increasing demand for thinning the semiconductor layer of the SOI substrate. On the other hand, the semiconductor layer of the SOI substrate varies in film thickness between substrates, and also varies not only between substrates but also within the substrate surface. This variation is about 25 nm. The variation in the film thickness of the semiconductor layer between the substrates or in the substrate surface is accompanied by a decrease in the characteristics and reliability of the formed transistor as the semiconductor layer of the SOI substrate is thinned.

  An object of the present invention is to provide a method for manufacturing a semiconductor device that can reduce variations in the thickness of a semiconductor layer of an SOI substrate.

  Another object of the present invention is to provide a processing apparatus capable of realizing a semiconductor device manufacturing method in which the thickness of a semiconductor layer of an SOI substrate is made uniform.

A method for manufacturing a semiconductor device of the present invention includes:
(A) preparing an SOI substrate in which a support substrate, an insulating layer, and a semiconductor layer are stacked;
(B) measuring the film thickness of the semiconductor layer;
(C) performing an oxidation process on the SOI substrate and forming an oxide film above the semiconductor layer;
(D) removing the oxide film,
The conditions for the oxidation treatment are determined based on the film thickness of the semiconductor layer measured in the step (b).

  According to the method for manufacturing a semiconductor device of the present invention, the SOI substrate is oxidized to oxidize a predetermined amount of the semiconductor layer, and then the obtained oxide film is removed to thereby remove the semiconductor layer of the SOI substrate. The film thickness can be controlled. At this time, the amount of the semiconductor layer oxidized by the oxidation treatment is determined based on the thickness of the semiconductor layer measured in advance before the oxidation treatment. Therefore, control can be performed so that a semiconductor layer having a desired thickness can be obtained, and a semiconductor device including an SOI substrate in which variation in the thickness of the semiconductor layer is reduced even between thin films and substrates can be manufactured. In addition, according to the method for manufacturing a semiconductor device of the present invention, there is an advantage that the film thickness of the semiconductor layer can be controlled according to the use of the user after purchasing the SOI substrate.

In the method of manufacturing a semiconductor device according to the present invention, forming another specific layer (hereinafter referred to as “B layer”) above a specific layer (hereinafter referred to as “A layer”) The case where the B layer is directly formed and the case where the B layer is formed via another layer on the A layer are included.

The method for manufacturing a semiconductor device of the present invention can further take the following aspects.

  In the method for manufacturing a semiconductor device according to the present invention, the step (c) may further include measuring a film thickness of the semiconductor layer.

  According to this aspect, the oxidation treatment can be performed while monitoring the change in the thickness of the semiconductor layer. Therefore, an SOI substrate having a semiconductor layer with a desired film thickness can be manufactured more reliably.

  In the method for manufacturing a semiconductor device of the present invention, the conditions for the oxidation treatment can be determined by adjusting at least one of temperature, in-plane temperature distribution of the semiconductor layer, and oxygen concentration in the reaction chamber.

  In the method for manufacturing a semiconductor device of the present invention, the film thickness of the semiconductor layer can be measured by a nondestructive measurement method.

  In the method for manufacturing a semiconductor device of the present invention, the measurement of the film thickness can be performed by a spectroscopic ellipsometer.

  In the method for manufacturing a semiconductor device of the present invention, in the step (c), the film thickness of the semiconductor layer can be measured in a state where the oxidation treatment is interrupted.

In the method for manufacturing a semiconductor device of the present invention, the oxidation treatment is performed by a processing apparatus using a plurality of heat source lights,
As the conditions for the oxidation treatment, the output of each heat source light can be determined by the in-plane distribution of the film thickness of the semiconductor layer.

  According to this aspect, when the oxidation treatment is performed by heat source light or the like, the output of the heat source light can be adjusted according to the in-plane film thickness variation, and the in-plane film thickness variation is further reduced. A semiconductor device including an SOI substrate can be manufactured. Here, the heat source light means light energy that can be a heat source exemplified by a halogen lamp or an arc lamp.

In the method for manufacturing a semiconductor device according to the present invention, the oxidation treatment is performed by a processing apparatus using heat source light,
The conditions for the oxidation treatment can determine the oxygen flow rate required for the oxidation treatment based on the in-plane distribution of the film thickness of the semiconductor layer.

  According to this aspect, the semiconductor device including the SOI substrate in which the flow rate of oxygen supplied during the oxidation process can be controlled in accordance with the in-plane film thickness variation, and the in-plane film thickness variation is further reduced. Can be manufactured.

The processing apparatus of the present invention includes a reaction chamber for oxidizing a substrate to be processed,
A film thickness measuring device that measures the film thickness of the substrate to be processed disposed in the reaction chamber.

  According to the processing apparatus of the present invention, the film thickness can be measured in a state where the substrate is disposed in a reaction chamber (hereinafter also referred to as “chamber”) in which an oxidation process is performed. Therefore, the film thickness of the predetermined layer can be measured while performing the oxidation treatment. For example, by monitoring the film thickness of the oxidized semiconductor layer, it is possible to determine whether to change the oxidation process condition, stop the oxidation process, or the like. As a result, a processing apparatus capable of manufacturing an SOI substrate controlled to a semiconductor layer having a desired thickness can be provided.

  In the processing apparatus of the present invention, the film thickness measuring device may be a spectroscopic ellipsometer.

1. Method for Manufacturing Semiconductor Device Hereinafter, a method for manufacturing a semiconductor device of the present invention will be described with reference to FIGS.

  First, as shown in FIG. 1, an SOI substrate 10A in which an insulating layer 12 and a semiconductor layer 14a are formed on a support substrate 10 is prepared. Next, the film thickness of the semiconductor layer 14a of the SOI substrate 10A is measured. Although the measuring method of this film thickness is not specifically limited, For example, it can measure with a spectroscopic ellipsometer. By measuring with a spectroscopic ellipsometer, there is an advantage that non-destructive measurement is possible.

Next, an oxidation process is performed on the SOI substrate 10A. As a result, as shown in FIG. 2, an oxide film 16 is formed on the semiconductor layer 14a. The conditions for the oxidation treatment are determined based on the film thickness of the semiconductor layer measured before the oxidation treatment. The conditions for the oxidation treatment include, for example, the temperature in the reaction chamber, the H ₂ O concentration, the atmospheric concentration distribution in the reaction chamber, the temperature distribution in the surface of the substrate to be processed, the oxygen flow rate supplied during the oxidation treatment, the treatment time, and the like. This can be done by controlling at least one of the following.

  Furthermore, the following method can be taken as adjustment of the conditions for the oxidation treatment. For example, when the oxidation treatment is performed by a processing apparatus having a plurality of heat source lights such as a halogen lamp, the output of each heat source light can be adjusted according to the variation in the film thickness within the substrate surface. For example, in the case where there is a thick region in the substrate surface as compared with other regions, the output of the heat source light in the thick region is increased to oxidize the semiconductor layer 14a in the thick region. Can be promoted compared to other regions. In addition to this, when the oxidation process is performed by a processing apparatus provided with a plurality of oxygen gas supply ports, the supply amount of oxygen required for the oxidation process is controlled in accordance with the variation in the film thickness in the substrate surface. be able to. For example, when there is a thick region in the substrate surface compared to other regions, the oxygen supply amount in the thick region is increased to oxidize the semiconductor layer 14a in the thick region. It can be promoted compared to other areas. The above control of the output of the heat source light and the control of the oxygen supply amount may be performed independently or in combination. In addition, the control of the output of the heat source light and the control of the oxygen supply amount are not limited as long as the conditions of the oxidation treatment can be controlled so as to make the in-plane variation of the semiconductor layer 14a uniform.

  Moreover, you may carry out, measuring the film thickness of the semiconductor layer 14a during this oxidation process. In the case of adopting this aspect, it is possible to determine the conditions for the subsequent oxidation treatment by reflecting the film thickness measured during the oxidation treatment. In this case, the processing is performed using a processing apparatus provided with a film thickness measuring device in the reaction chamber so that the film thickness of various layers can be measured in a state where the SOI substrate 10A is installed in the reaction chamber. For example, by performing the measurement while measuring the film thickness of the semiconductor layer 14a during the oxidation process, the oxidation process can be performed while reflecting the film thickness of the semiconductor layer 14a reduced by the oxidation process. The measurement of the film thickness is preferably performed in a state where the oxidation treatment is interrupted. This is because more reliable control can be performed by determining the conditions for the subsequent oxidation treatment based on the film thickness measured with the oxidation treatment interrupted.

  Next, as shown in FIG. 3, the oxide film 16 formed on the semiconductor layer 14a is removed. The removal of the oxide film 16 can be performed by a known general technique, for example, by isotropic wet etching. In this way, the SOI substrate 10A having the semiconductor layer 14 having a desired film thickness is formed.

  Next, for example, a MOS transistor (not shown) can be provided in the semiconductor layer 14. Hereinafter, an example of a manufacturing method for forming a MOS transistor will be described. First, a gate insulating layer is formed on the semiconductor layer 14 by, for example, a thermal oxidation method. Next, a conductive layer (not shown) is formed on the gate insulating layer, and this conductive layer is patterned to form a gate electrode. Next, a source region and a drain region are formed by introducing impurities of a predetermined conductivity type. Thus, the method for manufacturing the semiconductor device according to the present embodiment can be performed.

  According to the manufacturing method of the semiconductor device of the present embodiment, the oxide film 16 is formed by oxidizing the SOI substrate 10A by a predetermined film thickness in the semiconductor layer 14a. Thereafter, the thickness of the semiconductor layer 14 can be controlled by removing the obtained oxide film 16. At this time, the amount of the semiconductor layer 14a oxidized by the oxidation treatment is determined based on the film thickness of the semiconductor layer 14a measured in advance before the oxidation treatment. Therefore, it is possible to control to obtain a semiconductor layer having a desired film thickness, and it is possible to manufacture a semiconductor device including the SOI substrate 10 </ b> A having the semiconductor layer 14 in which the thinning and the variation between the substrates are reduced. As a result, the characteristics and reliability of various semiconductor elements such as MOS transistors formed on the SOI substrate 10A can be improved.

  In the method for manufacturing a semiconductor device of the present embodiment, the output of the heat source light and the oxygen supply amount are adjusted in accordance with the variation in the in-plane thickness of the semiconductor layer 14a when adjusting the conditions for the oxidation treatment. Thus, the speed of the oxidation treatment within the substrate surface can be adjusted. As a result, it is possible to manufacture a semiconductor device including the SOI substrate 10A having the semiconductor layer 14 with a uniform film thickness particularly in the substrate surface.

  In addition, by monitoring the film thickness of the semiconductor layer 14a and the oxide film 16 during the oxidation process and adjusting the conditions of the oxidation process as necessary, the SOI having the semiconductor layer 14 having a desired film thickness can be more reliably obtained. A semiconductor device including the substrate 10A can be manufactured. Therefore, it is possible to reduce both variations in film thickness between substrates and in the substrate surface.

  In addition, according to the method for manufacturing a semiconductor device of the present embodiment, there is an advantage that the film thickness of the semiconductor layer 14 can be controlled in accordance with the use of the user after purchasing the SOI substrate.

2. Next, the processing apparatus according to the present embodiment will be described with reference to FIG. First, the configuration of the processing apparatus will be described, and then the operation method of the processing apparatus will be described.

2.1. Configuration of Processing Apparatus FIG. 4 is a cross-sectional view schematically showing the processing apparatus 100 according to the present embodiment. FIG. 4 shows the reaction chamber 20 as a center. The processing apparatus 100 according to the present embodiment includes a reaction chamber 20, a heat source light 30, and a film thickness measuring device 40. The inner wall of the reaction chamber 20 is covered with a reflective material such as a mirror, for example. The reaction chamber 20 is provided with a support portion 22 for supporting the SOI substrate 10A, which is an object to be processed. The support 22 can be, for example, a pin made of quartz. A substrate to be processed is placed on the support portion 22. Various gas supply ports 24 are provided on the upper surface of the reaction chamber 20. An exhaust port 26 for exhausting the gas required for the reaction is provided on the side wall of the reaction chamber 20. A heat source light 30 is provided below the reaction chamber 20. For example, a halogen lamp or an arc lamp can be used as the heat source light 30. The heat source light 30 is covered with a reflector 32. As described above, the light emitted from the heat source light 30 is reflected by the reflecting material to heat the reaction chamber 20.

  Above the reaction chamber 20, a film thickness measuring device 40 for measuring the film thickness of various layers of the SOI substrate 10 </ b> A installed in the reaction chamber 20 is provided. In the present embodiment, a case where a spectroscopic ellipsometer is provided as the film thickness measuring device 40 will be described. The film thickness measuring device 40 includes a light source 42 and a detector 44 that detects the reflected wavelength. The light output from the light source 40 reaches the SOI substrate 10 </ b> A disposed in the reaction chamber 20 via the gas supply port 24, and the reflected light reaches the detector 44 from the other gas supply port 24.

2.2. Operation Method Next, the operation method of the processing apparatus 100 according to the present embodiment is described. First, an SOI substrate 10 </ b> A that is an object to be processed is installed in the reaction chamber 20. The SOI substrate 10 </ b> A is held in the reaction chamber 20 by the support portion 22. Next, a halogen lamp as the heat source light 30 is irradiated while introducing various gases such as oxygen gas and nitrogen gas. Thereby, thermal oxidation treatment is performed. At this time, the film thickness measuring device 30 appropriately measures the film thickness of the semiconductor layer 14a of the SOI substrate 10A. When measuring the film thickness, it is preferable to interrupt the irradiation with the heat source light 30. Next, based on the measured film thickness, the oxidation treatment conditions are set again so that the semiconductor layer 14a has a desired thickness, and then the oxidation treatment is continued. As described above, the oxidation treatment, the measurement of the film thickness, and the oxidation treatment under the conditions reflecting the measurement results are repeatedly performed in a state where the SOI substrate 10A is installed in the reaction chamber 20.

  After the thickness of the semiconductor layer 14a reaches the desired thickness, the oxidation process is terminated and the SOI substrate 10A is taken out from the reaction chamber 20. As described above, the processing apparatus 100 of the present embodiment can be operated.

  According to the processing apparatus 100 of this Embodiment, a film thickness can be measured in the state by which the to-be-processed object was put in the reaction chamber 20 which performs an oxidation process. Therefore, the film thickness of the predetermined layer can be measured while performing the oxidation treatment. For example, by monitoring the film thickness of the oxidized semiconductor layer, it is possible to determine whether to change the oxidation process condition, stop the oxidation process, or the like. As a result, it is possible to provide the processing apparatus 100 capable of manufacturing the SOI substrate 10A controlled to the semiconductor layer 14 having a desired thickness.

  The semiconductor device manufacturing method and the processing apparatus of the present invention are not limited to the above-described embodiment, and can be modified within the scope of the gist of the present invention. For example, in the manufacturing method of the semiconductor device according to the present embodiment, the case where the oxidation process is performed while monitoring the film thickness of the semiconductor layer 14a during the oxidation process has been described. While monitoring the thickness, it is also possible to control so as to obtain a semiconductor layer having a desired film thickness. Moreover, in the processing apparatus of this Embodiment, although the case where the film thickness measuring device 40 was installed above the reaction chamber 20 was demonstrated, it is not limited to this in particular, The board | substrate arrange | positioned in the reaction chamber 20 Any mode can be used as long as the film thickness of the predetermined layer can be measured.

Sectional drawing which shows typically the manufacturing process of the semiconductor device concerning this Embodiment. Sectional drawing which shows typically the manufacturing process of the semiconductor device concerning this Embodiment. Sectional drawing which shows typically the manufacturing process of the semiconductor device concerning this Embodiment. Sectional drawing which shows typically the processing apparatus concerning this Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Support substrate, 10A SOI substrate, 12 Insulating layer, 14a, 14 Semiconductor layer, 16 Oxide film, 20 Reaction chamber, 22 Support part, 24 Gas inlet, 26, Gas outlet 30 Heat source light, 32 Reflector, 40 Film Thickness measuring device, 42 light source, 44 detector 100 processing device

Claims (10)

(A) preparing an SOI substrate in which a support substrate, an insulating layer, and a semiconductor layer are stacked;
(B) measuring the film thickness of the semiconductor layer;
(C) performing an oxidation process on the SOI substrate and forming an oxide film above the semiconductor layer;
(D) removing the oxide film,
The method for manufacturing a semiconductor device, wherein the conditions for the oxidation treatment are determined based on the film thickness of the semiconductor layer measured in the step (b). In claim 1,
The step (c) further includes measuring the film thickness of the semiconductor layer. In claim 1 or 2,
The method for manufacturing a semiconductor device, wherein the condition for the oxidation treatment is determined by adjusting at least one of temperature, in-plane temperature distribution of the semiconductor layer, and oxygen concentration in the reaction chamber. In any one of Claims 1-3,
The method for manufacturing a semiconductor device, wherein the measurement of the thickness of the semiconductor layer is performed by a nondestructive measurement method. In claim 4,
The method for manufacturing a semiconductor device, wherein the film thickness is measured by a spectroscopic ellipsometer. In any one of Claims 2-5,
In the step (c), the measurement of the thickness of the semiconductor layer is performed in a state where the oxidation treatment is interrupted. In any one of Claims 1-6,
The oxidation treatment is performed by a processing apparatus using a plurality of heat source lights,
The condition for the oxidation treatment is a method of manufacturing a semiconductor device, wherein the output of each heat source light is determined by an in-plane distribution of the film thickness of the semiconductor layer. In any one of Claims 1-7,
The oxidation treatment is performed by a processing apparatus using a plurality of heat source lights,
The condition for the oxidation treatment is a method for manufacturing a semiconductor device, wherein an oxygen flow rate required for the oxidation treatment is determined by an in-plane distribution of the film thickness of the semiconductor layer. A reaction chamber for oxidizing the substrate to be processed;
A film thickness measuring device for measuring a film thickness of the substrate to be processed disposed in the reaction chamber. In claim 9,
The film thickness measuring instrument is a processing apparatus, which is a spectroscopic ellipsometer.

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