JPH05304102A - Fabrication of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent CVD and the like at unnecessary parts, which is a problem when outer peripheral clamps are employed, by introducing purge gas thereby supporting a substrate without requiring any outer peripheral clamp and to perform film deposition process and other processes with high surface uniformity by controlling purge gas flow. CONSTITUTION:The semiconductor fabrication system comprises a purge gas introduction mechanism (purge gas introduction holes 6) provided for a semiconductor substrate supporting table constructed integrally or divided into two sections, and purge gag flow rate control mechanisms (flow rate control valves 2) arranged on the semiconductor substrate supporting table at least two points thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device manufacturing apparatus, and more particularly, to a semiconductor device manufacturing apparatus having a process of processing using a gas flow during film formation. INDUSTRIAL APPLICABILITY The present invention can be used for manufacturing miniaturized LSIs and various semiconductor devices.

[0002]

2. Description of the Related Art Various techniques are used in the field of semiconductor manufacturing. For example, a metal CVD technique is used as a film forming technique, and among them, a blanket CVD technique and a selective growth CVD technique are, for example, a film forming technique of tungsten (W) and other materials, and are used for a multi-layer wiring forming process of the next generation ULSI. Various studies have been conducted as those that can be suitably used for technology and the like.

Blanket tungsten CVD, for example
Has been attracting attention as one of the technologies in the next-generation and subsequent ULSI multilayer wiring formation process technology that meets the demand for a technology for embedding fine contact holes and through holes of 0.35 micron rule or smaller with wiring materials.

[0004]

However, the metal thin film (especially tungsten thin film) formed by the blanket CVD method has poor adhesion to the substrate and is very easily peeled off. Therefore, in general, when forming a metal thin film on the substrate surface, an adhesion layer is required. In the case of blanket tungsten CVD, a TiN film is often used as an adhesion layer for this purpose. However, since the tungsten thin film is peeled off from the substrate portion where the TiN film is not formed, it is basically necessary to take measures to prevent the tungsten thin film from growing in such a portion.

In the conventional apparatus, as shown in FIGS. 5 and 6, a portion where the TiN thin film as the adhesion layer is not formed, that is, a clip mark portion of the TiN sputtering apparatus,
On the back surface of the wafer, a clamp mechanism is generally used to cover the outer peripheral portion of the substrate 8 by a clamp 13 that holds the outer periphery of the substrate 8 so that a tungsten thin film is not formed. However, the clamp 13
The attached tungsten film is easily peeled off, which causes particles. Such a clamp 13 supports the substrate 8 having a not-symmetrical shape such as having a notched edge portion 81 as shown in FIG. 7, for example. 5 and 6, 10 is a lamp, 12 is a gas supply port, 14 is a shower head, 15 is a substrate support base that is an alumina susceptor, and 16 is a transparent material window.

As a means for preventing the above-mentioned problems, as shown in FIG. 8, a purge gas (for example, Ar gas) is caused to flow from the peripheral portion of the substrate 8 (wafer) as shown by an arrow I, and the source gas ( A method of preventing the tungsten film from being deposited in a portion where TiN which is an adhesion layer is not formed is being studied by diluting the flow (indicated by arrow II) (11 in FIG. 8 is a gas duct). ).

However, a problem with such a technique being studied is that the distribution of the thin film formed on the wafer in the wafer surface is sensitively affected by the flow of the purge gas. For this reason, the uniformity has deteriorated due to the structure of the apparatus, particularly the clamp mechanism that disturbs the flow and the structure of the passage through which the purge gas flows. In particular, as shown in FIG. 7, the wafer that is the substrate 8 is generally not a perfect circle,
Since the shape has a notched edge portion 81 called an orientation flat in which a part of the arc is notched in a chord shape, the purge gas flow rate tends to increase on the notched edge portion 81 side,
This also causes the deterioration of the uniformity of the gas flow.
It is almost impossible to make these adjustments from the design stage of the device because of the problem of working accuracy.

[0008]

OBJECTS OF THE INVENTION The present invention solves the above problems and allows a substrate to be supported without a peripheral clamp, so that the presence of the clamp is a problem, ie a thin metal film on the part without the adhesion layer, for example in blanket CVD. Formation, or growth at unnecessary portions in selective growth CVD, can be controlled, and the flow of purge gas can be controlled to make uniform, so that film formation and other steps can be performed with good uniformity within the wafer surface. An object of the present invention is to provide a semiconductor device manufacturing apparatus having a simple structure.

[0009]

According to a first aspect of the present invention, in a semiconductor device manufacturing apparatus having a mechanism for introducing a purge gas into a semiconductor substrate support, a mechanism for controlling the flow rate of the purge gas is provided. A semiconductor device manufacturing apparatus characterized in that it is provided at least at two positions on a semiconductor substrate support, and thereby achieves the above object.

According to a second aspect of the present invention, the semiconductor substrate support is divided into at least two portions, that is, a portion that comes into contact with the semiconductor substrate and a portion that is in the outer peripheral portion of the semiconductor substrate and does not come into contact with the semiconductor substrate. 2. The semiconductor device manufacturing apparatus according to claim 1, wherein the purge gas passes between the divided semiconductor substrate supporting bases, thereby achieving the above object. ..

In the present invention, the purge gas is a generic term for gases that do not contribute to the reaction, and so-called dilution gas corresponds to the purge gas in the present invention. For example, A
r, He and other rare gases, nitrogen-based gases such as N ₂ gas that does not contribute to the reaction, and the like fall under this category, and even if they are active gases, they are gases that only act as a purge. Be done.

[0012]

In the semiconductor device manufacturing apparatus of the present invention, at least two or more flow rate control mechanisms are provided on the support for supporting the semiconductor substrate in order to control the flow of the purge gas. Flow control mechanism,
For example, the flow of the purge gas can be made uniform throughout the reaction chamber by controlling with a control mechanism at the gas outlet. As a result, the flow that flows from the wafer surface direction, for example, the symmetry of the flow of the raw material gas, is not broken, and film formation using gas can be performed uniformly and satisfactorily. For example, various types of CVD (blanket CVD or blanket CVD , Selective growth CVD, etc.), it is possible to uniformly deposit a predetermined thin film on the surface of a wafer which is a substrate.

[0013]

Embodiments of the present invention will be specifically described below with reference to the drawings. However, it should be understood that the present invention is not limited to the embodiments.

EXAMPLE 1 In this example, the present invention is applied to a semiconductor device manufacturing method in which a semiconductor device is manufactured by forming a film on a silicon wafer which is a semiconductor substrate by a blanket tungsten CVD technique.

The apparatus of the present embodiment has a semiconductor substrate supporting base,
In a semiconductor device manufacturing apparatus having a mechanism for introducing a purge gas, as shown in FIG. 1, a mechanism for controlling the flow rate of the purge gas is provided in at least two locations on the semiconductor substrate support 1 (in the illustrated example, six locations are provided). ). In particular, in this example, the susceptor opening provided in the susceptor which is the support base 1 is used as the purge gas introducing hole 6, and the opening degree of the introducing hole is controlled by the flow rate control valve 2 to control the gas flow rate. Configured.

Generally, the uniformity of the flow rate of the purge gas on the surface of the substrate wafer cannot be maintained only by blowing the purge gas uniformly from the susceptor. That is, since there are structures having no symmetry, such as the clamp mechanism and the shape of the wafer (particularly the orientation flat shape), the purge gas cannot flow uniformly over the surface of the wafer by itself. Further, when the substrate support is divided and the support is formed from, for example, two portions of a quartz susceptor and a graphite susceptor, the uniformity may be disturbed due to a slight deviation of the positions of both portions. is there.

The non-uniformity of the purge gas affects, for example, the uniformity of the dilution amount of the raw material gas for film formation, and CVD
It adversely affects the film thickness uniformity. In addition, the uniformity during manufacturing is reduced.

In this embodiment, the uniformity of the purge gas is
As shown in FIGS. 1 to 3, a plurality of flow rate control valves 2 installed on a substrate support base 1 (susceptor) were used to make fine adjustments for improvement.

In this embodiment, to control the gas flow rate, the control valve adjusting screw 3 that is screwed into the screw fixing nut 4 fixed to the susceptor (graphite susceptor in the figure) that is the substrate support 1 is used. The size of the opening of the susceptor opening (purge gas introduction hole 6) is controlled by operating the flow rate control valve 2 that moves by turning the knob 5 and moves integrally therewith. The introduction hole 6 can be adjusted by, for example, blanket tungsten C.
Regarding the silane reduction reaction used during the nucleation of VD,
It is preferably used for adjusting the purge gas. Such CVD
Since the silane reduction used for tungsten nucleation in (1) is feed rate-controlled (the supply rate of the raw material gas is the rate-determining reaction, the nucleation changes significantly depending on the concentration of the raw material gas), so the distribution of the purge gas is extremely high. Sensitive to.

The in-plane uniformity of the purge gas in the system sensitive to the distribution of the purge gas may be measured, and the opening amount of the gas introduction hole 6 by the flow rate control valve 2 may be adjusted so that it becomes uniform. This in-plane uniformity can be known from the film thickness distribution of the generated film thickness. The film thickness distribution can be measured by the sheet resistance, and the purge gas flow can be recognized based on the measured sheet resistance and adjusted based on this.

In this example, the blanket tungsten CVD nucleation step was performed under the following conditions. Set temperature: 400 ° C. Raw material gas: WF ₆ / SiH ₄ = 10 / 7sc
cm Pressure: 60 Pa (0.5 Torr) Purge gas and flow rate: Ar = 150 sccm

In the present embodiment, by carrying out the above adjustment work, the flow rate of the purge gas becomes uniform, the disturbance of the uniformity of the flow of the raw material gas due to the flow of the purge gas can be prevented, and the purge gas is not used. It was possible to obtain at least the same level of in-plane uniformity as that of the conventional apparatus shown in FIG. If this adjustment work is performed once and then adjusted, the adjustment work can be continuously used as long as the conditions are not changed.

Therefore, according to the present embodiment, it is difficult to use the clamp gas mechanism in the purge gas type apparatus, which is capable of avoiding the problem of the particles peeling due to the deposition on the unnecessary portion and the particles caused by the deposition, without using the clamp mechanism. It is possible to solve the problem of occurrence of non-uniformity due to the above, and perform processing such as uniform film formation.

In the present embodiment, after the CVD or the like using the raw material gas with the purge gas, another metal is formed,
An insulating film (SiO ₂ or the like) may be formed, but at this time, this flow rate control mechanism can be used.

In this embodiment, the flow rate control means is a method of adjusting the valve 2 with a screw to change the size of the gas introduction hole 6, but any control means may be used.

Further, in the present embodiment, a jig for control adjustment is provided in the reaction chamber, but the adjustment may be performed from outside the reaction chamber by remote control. For example, in the case of changing the conditions, the flow rate is controlled in advance based on a prescribed parameter so that proper processing (proper CVD
Etc.) can be set. Examples of the mechanical means used for remote control from outside the reaction chamber include remote control means using a stepping motor.

According to this embodiment, without the outer peripheral clamp,
Since it is possible to prevent the formation of a metal thin film on the part where there is no adhesion layer and to control the flow of the purge gas, a metal thin film with good uniformity in the wafer surface can be obtained and a control mechanism is installed in the susceptor. Therefore, there is an advantage that the structure is simple.

Second Embodiment FIG. 4 shows the configuration of the second embodiment. In this embodiment, as shown in FIG. 4, a semiconductor substrate support is a substrate support portion 1 (a graphite susceptor in this example), which is a portion in contact with the semiconductor substrate, and a semiconductor substrate in the outer peripheral portion of the semiconductor substrate. Is separated into at least two or more of the supporting portion outer peripheral portion 7 (quartz susceptor in this example) which is a portion not to be formed,
The purge gas passes between the divided semiconductor substrate supports. In the figure, the flow of the purge gas is indicated by I, and the purge gas passage between the substrate supporting portion 1a and the outer peripheral portion 7 of the supporting portion is indicated by II.

In this embodiment, the purge gas flow rate is adjusted by using the same gas flow rate control mechanism as that used in the first embodiment.

In the case where the substrate support base is divided into two or more parts as in the present embodiment, conventionally, both parts, that is, the substrate support part 1a (graphite susceptor) in FIG.
The homogeneity of the gas flow was sometimes disturbed due to a slight shift in the mutual positions of the support and the outer peripheral portion 7 of the support (quartz susceptor). The gas flow distribution can be adjusted and the gas flow can be made uniform.

According to this embodiment, the same effect as that of the first embodiment can be obtained.

[0032]

According to the present invention, when a substrate can be supported without a peripheral clamp, and therefore the presence of a clamp is a problem, that is, formation of a metal thin film on a portion without a contact layer in blanket CVD, or selection. Growth CV
A device with a simple structure, which can prevent the growth in the unnecessary portion of D and can control the flow of the purge gas to make it uniform, and can perform film formation and other steps with good uniformity in the surface of the substrate. Can be provided.

[Brief description of drawings]

FIG. 1 is a plan view showing the configuration of a first embodiment.

FIG. 2 is a partially enlarged cross-sectional view showing the configuration of the first embodiment.

FIG. 3 is a partially enlarged plan view showing the configuration of the first embodiment,
It corresponds to the view in the direction of arrow III in FIG.

FIG. 4 is a sectional view showing a configuration of a second embodiment.

FIG. 5 shows the prior art.

FIG. 6 shows a conventional technique.

FIG. 7 shows a conventional technique.

FIG. 8 shows background art.

[Explanation of symbols]

 1 substrate support (graphite susceptor) 1a substrate support (graphite susceptor) 2 flow control valve 3 control valve adjusting screw 4 screw fixing nut 5 screw drive knob 6 purge gas introduction hole (susceptor opening) 7 support outer periphery (Quartz susceptor) 8 Substrate (wafer)

Claims (2)

[Claims] 1. A semiconductor device manufacturing apparatus having a mechanism for introducing a purge gas to a semiconductor substrate support, wherein a mechanism for controlling a flow rate of the purge gas is provided at least at two positions on the semiconductor substrate support. Semiconductor device manufacturing equipment. 2. A semiconductor substrate support is divided into at least two parts, a part that comes into contact with the semiconductor substrate and a part that is outside the semiconductor substrate and does not come into contact with the semiconductor substrate. 2. The semiconductor device manufacturing apparatus according to claim 1, wherein the purge gas passes between the substrate supporting bases.