JP2006202965A - Vaporizing apparatus and vaporizing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new type vaporizing apparatus for solving a problem which cannot be solved with the existing vaporizing apparatus, namely, for reducing flow rate of the carrier gas as much as possible or for achieving the carrier gas free vaporization and also for realizing various flow rates with only one apparatus. <P>SOLUTION: The vaporizing structure of the vaporizing unit (1B) of the vaporizing apparatus (A) realizes vaporization by heating liquid raw material (L) supplied from a liquid raw material supplying unit (1A). In the vaporizing structure, a vaporizing block (2) is accommodated within the vaporizing unit (1B), a formed vaporizing chamber (3) is provided with a gap (d) for the vaporizing block (2), and a spiral groove (4) for down-stream of the liquid raw material connected to the vaporizing chamber is formed to at least any of the internal circumference surface of the vaporizing chamber (3) or the external circumference surface of the vaporizing block (2). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vaporizer that converts a liquid material used in a semiconductor manufacturing process into a gas, and relates to a vaporizer that uses no carrier gas or allows a very small amount to flow.

  In recent years, the degree of miniaturization and high integration of silicon integrated circuit elements has been further advanced, and the film formation technology has further evolved accordingly. Recently, liquid raw materials such as TEOS are frequently used in the semiconductor thin film manufacturing process, but it is necessary to vaporize the liquid raw material accurately in a predetermined amount. The liquid raw material vaporization supply system has been commercialized. However, all of the conventional liquid material vaporization and supply systems use a large amount of carrier gas when vaporizing the liquid material. The reason for using the carrier gas is to facilitate the vaporization of the liquid raw material and to allow the vaporized gas to be rapidly transferred from the vaporizer to a film forming apparatus such as a CVD apparatus. As such a thing, there exists a vaporization apparatus by the present inventors as shown to Unexamined-Japanese-Patent No. 2001-11634 [patent document].

  Recently, however, there is a strong tendency to eliminate the use of carrier gas for further improvement of the film properties of the semiconductor thin film, and there is a strong demand for reducing the pressure in the reaction chamber of the film forming apparatus. It is strongly desired that the carrier gas for transporting the vaporized gas has a flow rate as small as possible, or that the carrier gas is zero, that is, the carrier gas is free. In addition, the amount of supply varies greatly depending on the process, and it was very difficult to cope with it.

JP2001-11634

  An object of the present invention is to provide a novel vaporizer capable of achieving a problem that cannot be dealt with by a conventional vaporizer, that is, making the carrier gas flow as small as possible, or achieving carrier gas free.

“Claim 1” relates to the vaporization structure of the vaporizer (A) of the present invention, “The vaporizer of the vaporizer (A) for heating and vaporizing the liquid raw material (L) supplied from the liquid raw material supplier (1A) ( 1B) vaporization structure,
A vaporization block (2) is housed in the vaporization section (1B), and a vaporization chamber (3) provided with a gap (d) between the vaporization block (2) is formed,
A spiral groove (4) for the flow of the liquid material that has entered the vaporization chamber is formed on at least one of the inner peripheral surface of the vaporization chamber (3) and the outer peripheral surface of the vaporization block (2). '' And

“Claim 2” relates to the basic form of the vaporizer (A) of the present invention: “a liquid raw material supply part (1A) for supplying a liquid raw material (L) to a vaporization part (1B) and a supplied liquid raw material (L) A vaporization unit (A) configured with a vaporization unit (1B) for heating and vaporization,
A vaporization block (2) is housed in the vaporization section (1B), and a vaporization chamber (3) provided with a gap (d) between the vaporization block (2) is formed,
At least one of the inner peripheral surface of the vaporization chamber (3) and the outer peripheral surface of the vaporization block (2) is formed with a spiral groove (4) for flowing down the liquid raw material that has entered the vaporization chamber (3). '' It is characterized by that.

  “Claim 3” is a modification of the vaporizer (A) according to claim 2, and “the liquid raw material supply part (1A) is a part for vaporizing the liquid raw material (L) remaining in the liquid raw material supply part (1A)”. (1B) is provided with a purge portion (1C) for pushing out ”.

  The liquid raw material (L) that has flowed into the vaporization chamber (3) is heated while flowing down the spiral groove (4) and gradually evaporates to form a raw material gas (G), which is formed from the vaporization section (1B). Supplied to the device. When the amount of inflow of the liquid raw material (L) is large, it flows into the vicinity of the lower end of the spiral groove (4), and when the amount of inflow is small, the evaporation is completed when it flows into the vicinity of the entrance of the spiral groove (4). . That is, regardless of the inflow amount of the liquid raw material (L), the entire amount can be gasified. The heat of gasification is supplied from the vaporizer body (1) that constitutes the outer peripheral surface of the vaporization block (2) and vaporization chamber (1B), and the liquid raw material (L) that has flowed into the gap (d) is vaporized. Evaporation of the liquid raw material (L) is completed when the carrier gas (K) is supplied from the block (2) or the vaporizing unit main body (1) without supplying the carrier gas (K) or very little. Most or all of the raw material gas (G) is a liquid raw material (L) gas. By providing the purge unit (1C), the entire amount of the liquid raw material (L) supplied from a liquid raw material mass flow meter (not shown) can be supplied to the vaporization (1B).

  Hereinafter, the present invention will be described in detail according to illustrated embodiments. FIG. 1 is an overall cross-sectional view of a first embodiment of a vaporizer (A) according to the present invention, which is roughly divided into a liquid raw material supply section (1A), a vaporization section (1B), and a liquid raw material supply conduit (9) for connecting the two. The liquid material supply unit (1A) is placed on the vaporization unit (1B) via a heat insulating member (not shown). As a modification of the present invention, there is a purge unit (1C) and a carrier gas supply unit (not shown) for supplying a small amount of carrier gas (K), but here they are of a basic type not attached These modifications will be described later.

  The liquid source supply unit (1A) includes an on-off valve (12) that houses an on-off valve drive element, a liquid source flow control valve (11) that contains a liquid source flow control valve drive element (13), and a flow control valve chamber. And an open / close valve (12) having a valve element (14) having an open / close valve drive element (15) and a liquid material flow rate control valve (11) having a liquid material flow rate control valve drive element (13). Are connected in series to control the opening and closing of the valve body (16) of the liquid material flow rate control valve (11). The open / close valve drive element built in the open / close valve (12) is pneumatically driven (or of course, an electric type using a solenoid or motor), and a drive gas supply nozzle (12a) is projected from the top. ing.

  The liquid source flow rate control valve (11) supplies the liquid source (L) sent from the liquid source mass flow meter (not shown) to the vaporization section (1B) at a predetermined flow rate, and the valve chamber (14 ) To control the opening degree of the liquid source supply outlet (10). The inlet of the liquid source supply hole (20) provided in the valve (1B) and communicating with the valve chamber (14) is connected to the liquid source mass flow meter, and the liquid source (L) having a predetermined mass flow rate is connected to the inlet. Receive supply. The liquid raw material supply outlet (21) of the valve chamber (14) and the liquid raw material inflow hole (7) of the vaporization section (1B) are connected by a liquid raw material supply conduit (9), and the liquid raw material (L) passes therethrough. And supplied to the vaporizing section (1B).

  In this embodiment, the vaporizer main body (1) is composed of a ceiling (b1), a cylindrical main body (b2), and a bottom (b3) .The main body (b2) has a heater (H1) and a temperature. A sensor (S1) is embedded and surrounds a cylindrical space formed in the cylindrical main body (b2) (this portion is referred to as a cylindrical cavity (31)). The vaporizer main body (1) has a ceiling surface (30) recessed in a conical shape on the lower surface of the ceiling (b1) and a cylindrical cavity (31) formed in the cylindrical main body (b2). ) (Which is referred to as a vaporization chamber (3)) is formed, and a vaporization block (2) formed in accordance with the shape of the inner surface of the vaporization chamber (3) is formed into a vaporization chamber (3 ).

  That is, as can be seen from the figure, the shape of the vaporization block (2) is conical at the top to form a conical upper end (40), and the portion below the conical upper end (40) is The cylindrical hollow portion (31) is formed in a columnar shape (this portion is referred to as a block main body (41)), and the vaporized block is formed by the conical upper end portion (40) and the block main body (41). (2) is formed. A heater (H2) is embedded in the center of the block body (41), and a temperature sensor (S2) is embedded in the vicinity of the outer peripheral surface. One or more spiral grooves (4) are formed on the outer peripheral surface of the block body (41), and the upper end of the spiral groove (4) is formed with a conical upper end (40) and a block body (41). It opens to the conical upper end (40) side at the boundary.

  And, inside the vaporization part (1B), a flow space (V) of the umbrella-shaped liquid raw material (L) is formed between the conical ceiling surface (30) and the conical upper end part (40). Is done. The shape of the flow space (V) is an umbrella shape in this embodiment, but may be a pyramid, a spindle shape, or a hemisphere as long as the liquid raw material (L) flows smoothly.

  On the other hand, the space between the inner peripheral surface of the cylindrical cavity (31) and the outer periphery of the block body (41) (in other words, the outer peripheral surface of the spiral strip (5) constituting the spiral groove (4)) is very narrow. A gap (d) is formed. This gap (d) allows a liquid source (L) gas (this is referred to as source gas (G)) to flow, but the width of the liquid source (L) cannot pass through, for example, 10 μm to 0.5 mm is selected. Further, the height (h) of the spiral strip (5) (in other words, the depth of the spiral groove (4)) is 0.5 mm to 1.5 mm, and the width (l) of the groove bottom is 1 mm to 3 mm. The width (W) of the base of the strip (5) is 0.5 mm to 1.5 mm. These numerical values are appropriately set according to the viscosity of the liquid raw material (L).

  A source gas outlet (18) is formed at the lower end portion of the cylindrical cavity (31), and the source gas outlet (18) is connected to a reaction chamber of a film forming apparatus such as a CVD apparatus. The source gas outlet (18) may be provided only at one position at the lower end portion of the cylindrical cavity (31), but a plurality of source gas outlets (18) may be formed evenly on the peripheral surface of the bottom. .

  The liquid raw material inflow hole (7) drilled in the ceiling (b1) of the vaporizer main body (1) is connected to the apex of the flow space (V) and passes through the liquid raw material supply conduit (9). The liquid raw material (L) is introduced from here into the flow space (V). Then, the liquid raw material (L) introduced into the flow space (V) flows down along the conical ceiling surface (30) or the conical upper end (40) to the outer peripheral surface of the block body (41). It flows into the engraved spiral groove (4) and flows down along the spiral groove (4).

  As shown in FIG. 5, the relationship between the spiral groove (4) and the cylindrical cavity (31) is that the gap (d) between them is very narrow, and the liquid raw material (L) that has flowed into this gap (d) However, due to the surface tension, a gap is selected such that it adheres and is held between the two and does not flow down.

  The spiral groove (5) forming the spiral groove (4) may be one or plural (multiple), and in this case as well, the optimum one is selected depending on the properties of the liquid raw material (L). The shape of the spiral strip (5) is not particularly limited. For example, the spiral strip (5) has a rectangular cross section (FIG. 7), a low trapezoid (FIG. 8), a trapezoid close to a triangle (FIG. 9), or a semicircular shape (FIG. 10) and so on. However, the trapezoidal, nearly trapezoidal, or semicircular shape of the trapezoidal shape that is lower in cross section than the rectangular shape, the liquid raw material (L) that has flowed into the spiral groove (4) can easily flow into the gap (d), as described later. The evaporation rate is accelerated.

  Next, the operation of the present invention will be described. When supplying the liquid source (L) to the reaction chamber of the film forming apparatus, the open / close valve (12) is kept open, and the liquid source (L) is supplied to the liquid source flow control valve (11). ing. The liquid material (L) is sent to a liquid mass flow meter (not shown), and the liquid material (L) having a set mass flow rate is sent to the flow control valve chamber (15) connected to the flow control valve (11). . Since the on-off valve (12) is in the open state as described above, the liquid material (L) reaches the valve seat (8) in which the liquid material supply outlet (10) of the flow control valve chamber (15) is formed. A mass flow control signal is sent from the liquid mass flow meter to the liquid raw material flow control valve (11), the valve opening is adjusted in accordance with the control signal, and the liquid raw material flow control valve (11) is set to a predetermined value. The liquid raw material (L) having only the mass flow rate is supplied to the vaporizing section (1B).

  The liquid raw material (L) flowing out from the liquid raw material supply outlet (10) opened to the flow control valve chamber (15) of the liquid raw material flow control valve (11) passes through the liquid raw material supply conduit (9) and is vaporized (1B). And is dropped into the flow space (V) from the liquid raw material inflow hole (7) opened at the top of the flow space (V). The liquid raw material (L) flowing into the flow space (V) flows down the conical ceiling surface (30) or the conical upper end (40) as it is, and finally reaches the outer periphery of the block body (41). It flows into the formed spiral groove (4).

  Since the block main body (41) and the vaporizing section main body (1) are heated by the heaters (H1) and (H2), the liquid films adhering to the outer and inner surfaces immediately rise in temperature, and the liquid raw material (L Part of) vaporizes. When the inflow amount of the liquid raw material (L) is small, all the liquid raw material (L) is heated and evaporated in the vicinity near the entrance of the spiral groove (4). On the contrary, when the inflow amount of the liquid raw material (L) is large, the liquid raw material (L) enters near the end of the spiral groove (4), and all the liquid raw material (L) is heated and evaporated in the meantime. Further, as shown in FIG. 4, the liquid raw material (L) flowing into the spiral groove (4) flows down along the spiral groove (4), the outer peripheral surface of the spiral strip (5), and the vaporization chamber (3). Although there is a thing that enters a slight gap (d) with the inner peripheral surface of the liquid, the former flows down while evaporating from the liquid surface, whereas the liquid raw material (L) entered the latter gap (d) As shown in FIG. 6, it rapidly evaporates upon receiving heat from the spiral strip (5) and the vaporizing section main body (1). Thereby, the liquid raw material (L) can be quickly vaporized without using the carrier gas (K) (or by supplying a very small amount of carrier gas as will be described later).

  Therefore, the cross-sectional shape of the spiral groove (4) is preferably trapezoidal, semicircular or triangular so that the liquid raw material (L) can easily flow into the gap (d). Also, the smaller the width (l) and depth (h) of the spiral groove (4), the more efficient the heat transfer of the liquid raw material (L), but if the amount is too small, the liquid raw material (L ) Decreases, the vaporization rate worsens, and the evaporation of the evaporated source gas (G) also worsens.

  The source gas (G) evaporated in this way flows along the spiral groove (4), flows toward the source gas outlet (18) of the vaporization section (1B), and in the gap (d), the liquid source ( When L) does not flow, it flows through this gap (d) toward the raw material gas outlet (6). When the supply of the liquid raw material (L) is completed, the on-off valve (12) is operated to close the liquid raw material supply outlet (10) of the flow control valve chamber (15), and the liquid raw material (L) to the vaporization section (1B) Is stopped.

  Next, a second embodiment will be described. Parts different from the basic example of the first embodiment will be described with emphasis, and the description of the first embodiment will be used for the corresponding parts. In the second embodiment, as shown in FIG. 2, the purge unit (1C) is included in the liquid source supply unit (1A). The purge section (1C) is composed of a two-way opening / closing valve, and is provided along with the liquid material flow control valve (11), and its purge gas outlet (50) is the root of the liquid material supply conduit (9), that is, the flow control. Connected directly under the valve chamber (15). The purge gas inlet (51) of the purge unit (1C) is connected to the purge unit gas supply conduit (52). When the supply of the liquid raw material (L) is completed and the on-off valve (12) is operated to close the liquid raw material supply outlet (10) of the liquid raw material supply conduit (9), the purge unit (1C) is operated and opened. The purge gas (P) is sent to the liquid source supply conduit (9), and the liquid source (L) remaining in the liquid source supply conduit (9) is pushed into the vaporization section (1B). As a result, all the liquid raw material (L) accurately measured and supplied by the liquid mass flowmeter is sent to the vaporizer (1B), where it is vaporized and supplied to the next film forming apparatus.

  In the first and second embodiments described above, the carrier gas (K) is not supplied, and only the source gas (G) in which the liquid source (L) is vaporized is described. However, the third embodiment described below is In this case, a very small amount of carrier gas (K) is supplied. In this case, as shown by the broken line in FIG. 3, a carrier gas supply through hole (60) is formed in the conical ceiling surface (30) of the vaporizer body (1), and the carrier gas supply through hole (60) is formed. A very small amount of a predetermined amount of carrier gas (K) is supplied to the flow space (V) via a mass flow meter that controls the mass flow rate of the carrier gas (K). This carrier gas (K) is supplied to the next film forming apparatus together with the source gas (G) vaporized in the vaporization section (1B). Since the supplied carrier gas (K) is very small, the internal pressure in the film forming apparatus is not greatly increased.

  The present invention can meet the demand for lowering the pressure in the reaction chamber of the film forming apparatus, and can greatly contribute to further improving the film characteristics of the semiconductor thin film.

Schematic sectional view of the first embodiment of the present invention Schematic sectional view of the second embodiment of the present invention Partial enlarged sectional view of the vaporization part of the present invention The partial expanded sectional view which shows the flowing-down state of the liquid raw material which flows through the vaporization chamber of this invention Partial enlarged view showing the relationship between the liquid material and the spiral groove Other enlarged views showing the relationship between the liquid material and the spiral groove Sectional view of the first embodiment of the spiral groove Sectional view of the second embodiment of the spiral groove Sectional view of the third embodiment of the spiral groove Sectional view of the fourth embodiment of the spiral groove

Explanation of symbols

(A) ... Vaporizer
(L) ... Liquid raw material
(1A) ... Liquid material supply unit
(1B)… Vaporizer
(1C)… Purge section
(G)… Raw material gas
(d) ... Gap
(1) ... Vaporizer body
(2)… Vaporization block
(3)… Vaporization room
(4) ... Spiral groove
(5) ... Spiral strip

Claims (3)

In the vaporization unit of the vaporizer that heats and vaporizes the liquid raw material supplied from the liquid raw material supply unit,
A vaporization block is housed in the vaporization section, and a vaporization chamber is formed in which a gap is provided between the vaporization block,
A vaporization structure of a vaporization device, wherein a spiral groove for flowing the liquid material that has entered the vaporization chamber is formed in at least one of the inner peripheral surface of the vaporization chamber and the outer peripheral surface of the vaporization block. In a vaporization apparatus configured with a liquid raw material supply unit that supplies a liquid raw material to a vaporization unit, and a vaporization unit that heats and vaporizes the supplied liquid raw material,
A vaporization block is housed in the vaporization section, and a vaporization chamber is formed in which a gap is provided between the vaporization block,
A vaporizer characterized in that a spiral groove for flowing down the liquid raw material that has entered the vaporization chamber is formed on at least one of the inner peripheral surface of the vaporization chamber and the outer peripheral surface of the vaporization block. The vaporizer according to claim 2, wherein the liquid source supply unit is provided with a purge unit for pushing out the liquid source remaining in the liquid source supply unit to the vaporization unit.

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