JP2001127057A - Method of heating substrate for semiconductor manufacturing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of heating a substrate for a semiconductor manufacturing equipment by which a change in film thickness of a first wafer can be suppressed when a plurality of wafers are consequently heat-treated. SOLUTION: A plurality of preliminarily prepared wafers are consequently carried into a processing chamber 2 of a heat treatment equipment 1, one at a time, and each wafer is heat-treated on a substrate supporting member 3, Before a wafer carried into the chamber 2 a first wafer is heat-treated, the processing chamber 2 is preheated to make the condition in the processing chamber 2 when it heat-treats the first wafer closer to one when it heat-treats the second wafer onwards, resulting on suppressing the decrease in film thickness of the first wafer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate heating method in a semiconductor manufacturing apparatus for heating a semiconductor wafer (substrate).

[0002]

2. Description of the Related Art A heat treatment apparatus, which is one type of semiconductor manufacturing apparatus, includes, for example, a processing chamber, a rotatable substrate supporting member installed in the processing chamber and supporting a semiconductor wafer, and an upper part of the substrate supporting member. A heating lamp arranged on the substrate and heating the semiconductor wafer supported by the substrate support member,
A temperature sensor provided on a base portion of the processing chamber and optically detecting a temperature of the semiconductor wafer. As the substrate support member, for example, there is a substrate support member including a cylindrical frame attached to a base portion of a processing chamber and a support ring frame coupled to an upper end of the cylindrical frame.

In the case of performing a heat treatment on a semiconductor wafer by the above-described heat treatment apparatus, a semiconductor wafer is supported by a substrate supporting member, is disposed at a predetermined position inside the processing chamber, and then a process gas is supplied into the processing chamber. Then, the semiconductor wafer is heated to a predetermined temperature using a heating lamp while rotating the substrate and monitoring the temperature of the semiconductor wafer with a temperature sensor.

[0004]

As the above-mentioned heat treatment apparatus, there is a single-wafer processing apparatus in which a plurality of wafers are prepared in advance and the plurality of wafers are sequentially heat-treated one by one. In a single-wafer heat treatment apparatus, generally, only one wafer is horizontally supported by a wafer support member, and heat treatment is performed.

[0005] In such a single-wafer heat treatment apparatus, I
When a wet oxidation process such as an SSG (In Situ Steam Generation) process is performed, an oxide film is formed on a first wafer (first wafer) of a plurality of prepared wafers to be sequentially heated, as compared with other wafers. There is a problem that the thickness becomes thin.

At this time, the reproducibility of film formation, which is one of the important performance conditions in mass-producing semiconductor devices, cannot be sufficiently obtained for the first wafer, so that quality stability and manufacturing efficiency are reduced. I will.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been made in consideration of the above problem, and has been made in consideration of the above problem. The aim is to provide a method.

[0008]

Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above-mentioned object, and as a result, during the first wafer heating process, the first wafer heating process is performed in comparison with the second and subsequent wafers. The present inventors have found that the inconsistency of processing conditions such as the temperature in the chamber causes a change in the film thickness to be formed, and arrived at the present invention.

That is, the substrate heating method according to the present invention comprises:
A substrate heating method in a semiconductor manufacturing apparatus, comprising: a processing chamber; and a substrate supporting member installed in the processing chamber and supporting a substrate to be processed, and performing a heating process on the substrate to be processed supported by the substrate supporting member. (1) a substrate preparation step of preparing a plurality of substrates to be processed at predetermined positions outside the processing chamber; (2) a preheating step of preheating the processing chamber in advance; and (3) a preheating step. A plurality of substrates to be processed are placed in a heated processing chamber.
A heat treatment step of sequentially carrying the sheets one by one and supporting each of the substrates by a substrate support member to perform a heat treatment.

In a semiconductor manufacturing apparatus such as a single-wafer type heat treatment apparatus, a predetermined number (a plurality) of substrates to be processed are formed into a set (lot), and a substrate heating process is performed for each substrate included in the lot as a work unit. Processing is performed. In this case, at the start of the substrate heating process, it is necessary to prepare a lot having a plurality of substrates to be transported, but this substrate preparation step requires a certain amount of time.

Therefore, the time interval from the end of the heating process to the last substrate in the previous lot to the start of the heating process to the first substrate (first wafer) in the lot is the time interval of the substrates belonging to the same lot. The time is longer than the time interval between the heat treatments. Therefore, during the heat treatment for the first substrate of the lot, the heat treatment conditions such as the temperature state in the processing chamber are different from the heat treatment conditions for the second and subsequent substrates performed in a stable state in the processing chamber. Become.

On the other hand, in the above-described substrate heating method, a plurality of substrates to be processed such as semiconductor wafers are prepared, and a heating process is performed on the inside of the processing chamber before starting the first substrate. Preheating is performed. Thus, the state in the processing chamber at the time of the heat treatment of the first substrate of the lot can be made close to the state of the heat treatment of the other substrate of the lot. Therefore, it is possible to suppress a change in a film formation state such as a decrease in an oxide film thickness that occurs on a substrate that is first heat-treated.

Here, the preheating step is preferably performed simultaneously with the substrate preparation step. As mentioned above,
A certain amount of time is required for the substrate preparation step, and by performing preheating simultaneously using that time,
The additional time required for performing the preheating can be reduced, and the temporal processing efficiency can be improved.

In the preheating step, the temperature of the preheating is preferably set lower than the temperature of the heat treatment in the heat treatment step. During the heating process, the substrate to be processed is supported by the substrate support member in the processing chamber, so that heating of a part of the processing chamber is suppressed. Therefore, in the preheating performed without the substrate to be processed, by setting the heating temperature of the preheating to be lower than the heating temperature of the heat treatment, the excessive heating of the part where the heating is originally suppressed is suppressed. In addition, the state in the processing chamber can be suitably maintained. Such a temperature setting is actually performed by setting the heating power from a heating means such as a lamp to be lower than that during the substrate heating process. As the setting, for example, there is a setting in which the heating power from the lamp is set to about 25% as compared with the heating power at the time of the heat treatment.

In the preheating step, the effect of the preheating differs depending on the atmosphere in the processing chamber when preheating is performed. As a gas atmosphere in which a sufficient effect can be obtained, at least one of N ₂ , H ₂ , and O ₂ is used.
It is preferable to use a gas atmosphere containing two components.

Furthermore, in the preheating step, the effect of the preheating also varies depending on the time of the preheating, but the preheating time of 3 minutes or more is sufficient for improving the film formation state. It is preferable to secure the effect. However, if the preheating time is too long, the improvement in the effect of the improvement will be reduced, and the temporal production efficiency will decrease. Therefore, it is preferable to set the preheating time to 3 minutes, for example.

It is preferable that the preheating in the preheating step and the heat treatment in the heat treatment step are performed using the same heating means. In this case, there is no need to change the configuration of the semiconductor manufacturing apparatus itself such as a heat treatment apparatus for performing a heat treatment, so that the above-described substrate heating method can be easily realized. In addition, as a heating means, there is a configuration using a plurality of heating lamps or the like.

Further, in the preheating step, the preheating may be performed in a state where the preliminary substrate for preheating is supported by the substrate supporting member. As described above, by setting the spare substrate at a position where the substrate to be processed is located at the time of performing the heat treatment and performing the preliminary heating, it is possible to prevent an excessive rise in temperature in a portion that is not heated during the execution of the heat treatment in the processing chamber. it can.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a substrate heating method in a semiconductor manufacturing apparatus according to the present invention will be described below in detail with reference to the drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description. Also, the dimensional ratios in the drawings do not always match those described.

FIG. 1 is a perspective view showing a partial cross section of a heat treatment apparatus as an embodiment of a semiconductor manufacturing apparatus used in a substrate heating method according to the present invention, and FIG. 2 is a partially enlarged cross sectional view of the heat treatment apparatus. It is. The heat treatment apparatus 1 shown in FIGS. 1 and 2 performs a single-wafer rapid heat treatment (RT) for performing a heat treatment on a silicon wafer (substrate) W as a substrate to be processed one by one.
P, Rapid Thermal Processing) apparatus, and includes a processing chamber 2 including a base 2a, a side wall 2b, and a lid 2c.

The wafer W to be heated by the heat treatment apparatus 1 is not shown in FIG. 1 but shows only the configuration of the apparatus, and FIG. 2 shows a state where the wafer W is installed. In addition, as the substrate to be processed, there are substrates such as a semiconductor wafer and a glass substrate. Hereinafter, a case where a silicon wafer is used will be described.

In the processing chamber 2, a substrate supporting member 3 for supporting the wafer W is provided. The substrate support member 3 includes a cylindrical frame 5 rotatably mounted on a base 2a via a bearing 4 and a ring frame 6 provided at an upper end of the cylindrical frame 5. A supporting step 6a for supporting the edge of the wafer W is formed on the inner edge.

Here, in a state where the wafer W is supported by the substrate supporting member 3 (see FIG. 2), the substrate supporting member 3 including the base portion 2a, the cylindrical frame 5 and the ring frame 6 is provided on the back side of the wafer W. , A wafer back side space Sa surrounded by the wafer W is formed.

A lift member 7 for supporting the wafer W transferred into the processing chamber 2 by the transfer robot (not shown) on the substrate support member 3 is provided below the base 2a. The lift member 7 has a plurality (for example, three) of support pins 8 that lift the wafer W through the base portion 2a.

A lamp group 9G comprising a plurality of heating lamps 9 as heating means for heating the wafer W supported on the substrate supporting member 3 is disposed above the lid 2c of the processing chamber 2. The cover 2c is provided with a circular lamp window Lw, and heat of the heating lamp 9 is applied to the lamp window L.
w to the wafer W. Also, the base part 2a
A temperature sensor 1 for optically detecting the temperature of the wafer W
0 is provided.

The temperature sensor 10 has a predetermined angle (for example, 9 mm) including a center and a part of a peripheral edge of a circular plate 11 surrounded by the substrate supporting member 3 in the base portion 2a.
For example, as shown in FIG. 1, a plurality of sensors are incorporated in a substantially fan-shaped sensor installation area having 0 degrees. The above-mentioned space Sa on the back side of the wafer is an optically completely closed space. Therefore, by utilizing this closed space Sa, the temperature of the wafer W is measured using a temperature sensor for optically measuring the temperature. Temperature can be detected.

On the side wall 2b of the processing chamber 2, a gas supply port 12 and a gas discharge port 13 are provided to face each other. The gas supply port 12 is connected to a gas supply system (not shown) for supplying a process gas to the wafer surface side space Sb on the surface side of the wafer W in the processing chamber 2. Further, a gas discharge system (not shown) for discharging gas in the wafer surface side space Sb to the outside of the processing chamber 2 is connected to the gas discharge port 13.
Here, the process gas is a gas used for the process.

Here, a procedure for heating the wafers W one by one using the heat treatment apparatus 1 configured as described above will be described. First, a wafer W to be processed is transferred into the processing chamber 2 by a transfer robot (not shown). Then, the three support pins 8 are lifted by the lift member 7 to lift the wafer W, and then the support pins 8 are lowered to move the wafer W to the ring frame 6 of the substrate support member 3.
It is placed on the upper predetermined position.

Subsequently, the process of heating the wafer W is started. First, a process gas is supplied from the gas supply port 12 to the wafer surface side space Sb. Then, the driving means (not shown) rotates the substrate support member 3 to rotate the wafer W, and turns on the plurality of heating lamps 9 of the lamp group 9G located above the wafer W. As a result, the temperature of the wafer W gradually increases, and a heating process is performed on the wafer W. Thereafter, when a predetermined time has elapsed, the rotation of the wafer W is stopped, the heating process is terminated, and the wafer W is taken out of the processing chamber 2 by the transfer robot.

The heat treatment apparatus 1 shown in FIGS. 1 and 2 is of a single-wafer type as described above, and the wafers W to be processed are supported by the substrate supporting members 3 one by one to perform the heat treatment. In such a single-wafer heat treatment apparatus 1, a plurality of wafers W may be sequentially subjected to heat treatment. That is, two or more predetermined numbers of wafers W are set as a lot (set) WL, and the wafer heating process is performed using the heating process for each of the wafers W included in the lot WL as one work unit.

In this case, a wafer lot WL including a predetermined number of wafers W is prepared outside the processing chamber 2 and arranged at a predetermined position.
The wafers W from L are sequentially transferred one by one into the processing chamber 2 of the heat treatment apparatus 1, and the respective wafers W are subjected to a heat treatment.

FIG. 3 is a block diagram schematically showing one embodiment of such a semiconductor manufacturing apparatus including the heat treatment apparatus 1. In the present embodiment, a load lock device (load lock chamber) L is used to prepare a wafer lot WL outside the processing chamber 2 of the heat treatment apparatus 1.

The heat treatment apparatus 1 and the load lock apparatus L are provided with gas processing systems 1a and La, respectively. The gas processing systems 1a and La are respectively a gas supply system,
It is configured to include a gas exhaust system and a control system. The vacuum processing in the heat treatment apparatus 1 and the load lock apparatus L, the adjustment of the gas atmosphere, the supply and exhaust of the process gas, and the like are performed by these gas processing systems 1a and La. Done by The transfer of the wafer W from the load lock device L to the heat treatment device 1 is performed by the transfer robot T.

The heat treatment device 1, the load lock device L, the transfer robot T, and the gas treatment systems 1a and La
The operation of each is controlled by the substrate heating processing control device C. Each step of the substrate heating method described later by the semiconductor manufacturing apparatus is performed based on control of each unit by the substrate heating processing control device C. In the following, each of the wafer lots WL has 25 wafers W1 to W1.
W25.

A method of heating a substrate in a semiconductor manufacturing apparatus having the heat treatment apparatus 1, the load lock apparatus L, and the transfer robot T configured as described above will be described. FIG.
4 is a timing chart showing one embodiment of a substrate heating method using the semiconductor manufacturing apparatus. The substrate heating method according to the present embodiment includes three steps of a substrate preparation step S1, a preliminary heating step S2, and a heat treatment step S3.

In the substrate preparation step S1, the load lock operation of the wafer lot WL including the 25 wafers W1 to W25 and the wafer mapping of the load locked wafers W1 to W25 are performed. First, after the wafer lot WL to be subjected to the wafer heating process is set at a predetermined position in the load lock device L, the door is closed and the inside of the load lock device L is sealed (step S11), and the sealed load lock device L is set. The inside of L is evacuated (step S12).

Next, O in the load lock device L
_{2 A} cycle purge is performed to sufficiently reduce the amount of (oxygen) and the like (step S13). In this cycle purge, a predetermined pressure, for example, 2.7 kPa (20 To
rr), the supply of N ₂ (nitrogen) gas and the evacuation are repeated a plurality of times, for example, five times. Thus, the amount of O ₂ in the load lock device L is sufficiently reduced. When the cycle purge is completed, N ₂ gas is gradually introduced into the load lock device L in a vacuum state to a pressure set at the time of executing the heating process, for example, 1.3 kPa (10 Torr). Is increased (step S14).

After the end of the cycle purge, the wafer mapping of the load-locked wafer lot WL is started simultaneously with the start of the introduction of the N ₂ gas (step S15). In the wafer mapping, each wafer W1 to W of the wafer lot WL is
It is checked whether the devices 25 are respectively located at the correct positions in the load lock device L. Here, in the load-locked wafers W1 to W25, the arrangement state such as the position may change due to a change in pressure during evacuation and cycle purge. Therefore, this wafer mapping is performed after the evacuation and the cycle purge are completed.

On the other hand, in the heat treatment apparatus 1 for performing a heat treatment on each wafer, a preliminary heating step S2 is performed prior to the heat treatment step S3. That is, the inside of the processing chamber 2 (see FIGS. 1 and 2) of the heat treatment apparatus 1 is preliminarily heated by preheating for a predetermined time (step S21). This preheating is performed using a plurality of heating lamps 9 used for normal wafer heating processing. In particular, in the present embodiment, this preheating is performed in parallel with each operation of the substrate preparation step S1.

When the above-described wafer mapping in the load lock device L is completed, the heat treatment device 1
After finishing the preheating (preheating) in the processing chamber 2,
The substrate heating step S3 is started. This wafer heating process is sequentially performed on each of the wafers W1 to W25 of the wafer lot WL one by one.

First, the first wafer (first wafer) W1 of the wafer lot WL arranged in the load lock apparatus L is taken out by the transfer robot T, transferred into the heat treatment apparatus 1 and placed on the substrate support member 3. It is supported at a predetermined position (step S31). Then, with respect to the wafer W1, which is a substrate to be processed, supported by the substrate support member 3,
The above-described heating process is performed using the plurality of heating lamps 9 (Step S32). When the heating process is completed, the wafer W1 is carried out of the heat treatment apparatus 1, and thereafter, the wafer transfer (step S31) and the heating process (step S31) are performed on the second and subsequent wafers W2 to W25, respectively.
32) is performed.

The effect of the substrate heating method according to the above embodiment will be described together with specific examples.

In the single-wafer heat treatment apparatus 1 in which the wafer W is subjected to the heat treatment one by one, a plurality of wafers (for example, wafer lots) are placed at predetermined positions (for example, wafer lots) outside the processing chamber 2 before the start of the wafer heat treatment. Load lock device L
Be prepared in). In this case, some time is required for preparing these wafers. For example, in the substrate preparation step S1 in the embodiment shown in FIG. 4, about 180 seconds are required for load lock and wafer mapping.

On the other hand, the same prepared wafer lot WL
The time interval when sequentially performing the heat treatment on each wafer included in the above is sufficiently short as compared with the above-described load lock required time. Therefore, the heating processing conditions such as the temperature in the processing chamber 2 for the first wafer W1 for which time has elapsed before the start of the heating processing are different from those of the other wafers W2 to W25.
Is different from the heat treatment conditions.

At this time, there is a problem (first wafer effect) that the film thickness formed on the first wafer W1 among the wafers of the wafer lot WL is reduced due to the difference in the heat treatment conditions described above. Such a problem is particularly problematic in rapid thermal processing (RTP) devices.
Appears remarkably when a wet oxidation process such as an SG (In Situ Steam Generation) process is performed, and causes a reduction in the film thickness of, for example, about 3% in the first wafer.
In other processes, the same first wafer effect may be generated.

Here, the ISSG process means that H ₂ and O ₂ are supplied without directly supplying H ₂ O molecules, and H ₂ O (steam) is converted from these H ₂ and O ₂ in the processing chamber 2. This is one type of wet oxidation process in which an oxide film is formed by generation. In this method, since steam is generated in the processing chamber 2, it is considered that the above-described first wafer effect becomes particularly remarkable.

FIG. 5 is a graph showing a change in film thickness due to a first wafer effect in such a heat oxidation process. Here, changes in average film thickness and film thickness uniformity when the heating process is performed in a state where a time has elapsed since the end of the previous substrate heating process are shown, and the horizontal axis of the graph is the end of the previous substrate heating process. Elapsed time since (min)
The vertical axis indicates the average film thickness (%) and the film thickness uniformity (%) when the film thickness formed by the heating process in a stable state is taken as 100%.

The film thickness was measured using a FOCUS ellipsometer F
3m from the edge of 200mm wafer using E-III
The film thickness was measured at 49 equally spaced points in the wafer plane from the inside excluding the portion of m, the average value of the measured values was used as the film thickness, and 1 sigma (standard deviation) of the measured value distribution was used as the film thickness. Shown as thickness uniformity. Note that the film thicknesses shown in the following graphs are all based on the assumption that the film thickness formed by the heating process in a stable state is 100%.

The heating process for film formation is ISS.
This is performed using the G process. Specifically, heat treatment is performed at a processing temperature of 1100 ° C. and a processing time of 90 seconds, and H ₂ 33 is used as a process gas supplied into the processing chamber 2.
% / O ₂ 67% mixed gas at 18 l / min (slm, s
tandard l / min) at a flow rate of 1.3 kPa
(10 Torr) and a heating process was performed.

Among these, as for the film thickness, the film thickness to be formed decreases as the time elapses from the end of the previous heat treatment to the start of the next heat treatment. The film thickness was reduced to about 98.7%, and after a lapse of more time, almost equilibrium was reached after 5 minutes, and 98%
The film thickness is as follows. That is, from the stage where the elapsed time exceeds about 3 minutes, the first wafer effect in which the film thickness is reduced becomes remarkable. Further, the uniformity of the film thickness is less affected than the film thickness, but the uniformity is slightly reduced due to the lapse of time from the end of the previous heat treatment.

In order to solve the problem of the first wafer effect such as the reduction in film thickness, in the above-described substrate heating method, the preheating in which the inside of the processing chamber 2 of the heat treatment apparatus 1 is preliminarily heated before the wafer heating processing is started. It is carried out.
As a result, the state in the processing chamber 2 can be brought close to the state immediately after the completion of the wafer heat treatment, and therefore, it is possible to reduce the first wafer effect such as a decrease in film thickness.

It is preferable that such preheating is performed by using the same heating means as that used in the wafer heating process. At this time, preheating can be performed without providing new heating means for preheating, and, for example, a conventional heat treatment apparatus can be used as it is without changing its configuration. Suitable heating means include, for example, a lamp group 9G including a plurality of heating lamps 9 shown in the heat treatment apparatus 1 described above.

It is preferable that the heating temperature of the preheating at this time is set to a temperature lower than the heating temperature in the wafer heating process. During the wafer heating process, the wafer W is supported by the substrate heating member 3, and therefore, for example, heating light from the plurality of heating lamps 9 is not directly irradiated on the surface of the circular plate 11. On the other hand, at the time of preheating, a portion that is not usually directly heated such as the circular plate 11 may be excessively heated. Therefore, by setting the preheating temperature low,
It is possible to obtain a temperature state in the processing chamber 2 closer to a state immediately after the completion of the wafer heating processing. actually,
Such a temperature condition is realized by setting the heating power by the heating unit to be smaller than that during the wafer heating process (for example, to a heating power of 25%).

The preheating step S2 including the preheating is performed in the same manner as in the example shown in FIG.
It is preferable to carry out simultaneously with 1. At this time, the work time additionally required by executing the preheating step is reduced, so that the time efficiency of the wafer heating process is improved. Here, the time for preparing the substrate and the time for performing the preheating are determined, for example, in FIG.
15 seconds after the end of the preheating (step S2)
As in the case where 1) has been completed, they do not always have to completely match. However, it is also possible to terminate the preheating at the same time as the completion of the wafer mapping, and immediately start the wafer transfer and heating process.

The preferred conditions for the preliminary heating of the inside of the processing chamber 2 by preheating will be further examined. In the following, the pressure during preheating is set to 1.3 kPa (10 Torr).

FIG. 6 shows a processing channel for performing preheating.
4 is a graph showing the influence of a gas atmosphere in a bar 2.
Each graph is from the left, when preheating is not performed.
If N _TwoPerformed preheating in 100% atmosphere
For example, H_TwoExample performed in 100% atmosphere, H_Two50% /
O_TwoExample performed in 50% atmosphere, O_Two100% atmosphere
2 shows an embodiment performed with care. With each of these data
Are gas flow rates of 5 l / min (slm, standart
 l / min) for 60 seconds of preheating. Ma
The wafer heating process after preheating is described above with reference to FIG.
Performed under the same conditions
The heating power from the step 9 is 25% of the wafer heating process.
It is set to constant.

According to this data, the ratio without preheating is
In the comparative example, about 3% due to the first wafer effect
Near film thickness reduction has occurred. On the other hand,
In each of the four embodiments, the reduction in film thickness was suppressed.
You can see that it is done. In this embodiment,
Is O in each gas atmosphere_TwoThose using gas atmosphere
The improvement effect of the film thickness is the highest, and the film thickness reduction is about 2
%. Therefore, these
N_Two, H_TwoOr O_TwoContaining at least one of the following
The atmosphere is suitable for preheating.
is there. Among them, O _TwoGas atmosphere, especially decrease in film thickness
It is preferred as being suppressed.

FIG. 7 is a graph showing the effect of the preheating time when performing preheating. Each graph shows an example in which preheating was performed with a preheating time of 60 seconds when preheating was not performed, and a preheating time of 1 when the preheating was not performed.
An example performed in 80 seconds and an example performed in a preheat time of 600 seconds are shown. In each of these data, the gas atmosphere was N ₂ 100% and the gas flow rate was 5 l / mi.
Preheating is performed at n (slm, standartl / min). Further, the wafer heating process after the preheating is performed under the same conditions as described above with reference to FIG. 5, and the heating power from the plurality of heating lamps 9 during the preheating is increased by 25% during the wafer heating process.
It is set constant at%.

In this data, data at a preheating time of 60 seconds (same as N ₂ 100% data in FIG. 6)
In comparison with the above, a sufficient effect of suppressing a decrease in film thickness, which is three times or more in the preheating time of 180 seconds, is obtained. Further, when the preheating time is 600 seconds, the obtained film thickness is further improved. From these data, in order to sufficiently improve the film thickness, the preheating time is preferably set to 180 seconds (3 minutes) or more.

In the case of the preheating time of 600 seconds, the film thickness is improved as compared with the case of the preheating time of 180 seconds, but the efficiency of improving the film thickness after exceeding 180 seconds gradually decreases. However, the effect obtained with respect to the time used for preheating is somewhat small. Therefore, it is preferable to select a suitable preheating time within a range that does not reduce the manufacturing efficiency, from the required film thickness accuracy and the preheating time. For example, it is preferable to set the preheating time to 180 seconds (3 minutes). Note that the preheat time may be set to 180 seconds or less depending on conditions.

When the preheating is performed simultaneously with the preparation of the substrate, the preheating time is preferably determined in consideration of the time required for preparing the substrate. For example, in the embodiment of the substrate heating method shown in the timing chart of FIG.
One takes about 180 seconds. Therefore, in the above-described example, by setting the preheating time to 180 seconds from this point as well, it is possible to achieve both improvement in the temperature state in the processing chamber 2 and improvement in the temporal production efficiency.

FIG. 8 is a graph for comparing the film thickness in a state where the inside of the processing chamber 2 is stable with the film thickness in the first wafer. In each graph, graph A shows the case where preheating was not performed, and graph B showed N _{2 at a} flow rate of 5 l / min.
An example in which preheating was performed for 1 minute in a gas atmosphere, and a graph C shows an example in which preheating was performed for 3 minutes in an O ₂ gas atmosphere at a flow rate of 5 l / min. The heating power of the lamp at the time of preheating is set to 25%. As shown in this figure, by performing preheating in the processing chamber 2 before the start of the heat treatment on the first wafer, a decrease in the film thickness due to the first wafer effect is suppressed. Further, by selecting the gas atmosphere and the preheating time, the efficiency of improving the film thickness can be improved or adjusted. For example, in the example shown in the graph C in which preheating was performed for 3 minutes in an O ₂ gas atmosphere, the decrease in film pressure was suppressed to 2% or less.

The above-mentioned film thickness reduction occurs for the first wafer W1 of each wafer in the wafer lot WL, but the film thickness reduction is small for the second wafer W2 and the third and subsequent wafers. Wafers W3 to W25 are in a stable state where little decrease in film thickness is observed.

The substrate heating method in the semiconductor manufacturing apparatus according to the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the substrate preparation step S1 for preparing a plurality of substrates to be processed is not limited to the case where the load lock and the wafer mapping shown in FIG. It is possible to carry out a preheating step as well.

As a semiconductor manufacturing apparatus to which such a substrate heating method is applied, the present invention can be applied to a semiconductor manufacturing apparatus other than the above-described heat treatment apparatus. For example, a heating unit having a configuration other than the heating lamp 9 may be used. Alternatively, a heating lamp for preliminary heating may be provided separately from the wafer heating process.

In the above embodiment, preheating is performed without placing a wafer in the processing chamber 2 in order to simplify the preheating operation. However, if necessary, the substrate supporting member 3 is preheated. The preheating may be performed while supporting a spare wafer (dummy wafer) for use. Regarding the temperature during preheating, if necessary even when a dummy wafer is installed or when a dummy wafer is not used, preheating is performed at a temperature (power) higher than the heating temperature (heating power) during wafer heating processing. Is also good.

[0067]

The substrate heating method according to the present invention has the following effects as described in detail above. That is,
In a substrate heating process in which a plurality of substrates to be processed such as a wafer lot including a plurality of wafers are prepared at predetermined positions, and the substrates to be processed are sequentially transferred one by one into the processing chamber 2 and installed to perform a heating process, Alternatively, after the substrate is prepared and before the substrate heating process is started, the inside of the processing chamber is preliminarily heated by preheating. With this, the state in the processing chamber at the time of the heating process for the first substrate (first wafer) of the plurality of substrates to be heated is made closer to the state for the second and subsequent substrates, and It is possible to suppress a decrease in film thickness due to a first wafer effect due to a difference in temperature state in the inside.

At this time, since the reproducibility of the oxide film thickness generated by the substrate heat treatment such as the ISSG process in the rapid thermal processing (RTP) apparatus is improved, the stability of the quality obtained by the heat treatment and the improvement of the production efficiency are improved. Is realized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a partial cross section of an embodiment of a heat treatment apparatus which is a semiconductor manufacturing apparatus.

FIG. 2 is a side sectional view showing a part including a processing chamber of the heat treatment apparatus shown in FIG. 1;

FIG. 3 shows a heat treatment apparatus, a load lock apparatus, and a load lock apparatus shown in FIG.
1 is a block diagram schematically illustrating an embodiment of a semiconductor manufacturing apparatus having a transfer robot.

4 is a timing chart showing one embodiment of a substrate heating method using the semiconductor manufacturing apparatus shown in FIG.

FIG. 5 is a graph showing a decrease in film thickness in a first wafer.

FIG. 6 is a graph showing the effect of preheating on the gas atmosphere.

FIG. 7 is a graph showing the time dependence of the effect of preheating.

FIG. 8 is a graph showing an effect of suppressing a decrease in film thickness due to preheating.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Heat treatment apparatus, 2 ... Processing chamber, 2a ... Base part,
2b ... side wall part, 2c ... lid part, 3 ... substrate support member, 4 ... bearing, 5 ... cylindrical frame, 6 ... ring frame, 6
a: Support step, 7: Lift member, 8: Support pin, 9:
Heating lamp, 9G: lamp group, 10: temperature sensor, 11
... Circular plate, 12 ... Gas supply port, 13 ... Gas discharge port, L ... Load lock device, T ... Transport robot, C ... Substrate heating control device.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Seiya Urushizaki 14-3 Shinizumi, Narita-shi, Chiba Applied Materials Japan Co., Ltd. (72) Inventor Yuji Maeda 14-3 Shin-izumi, Narita-shi, Chiba Nogedaira Industrial Park Applied Materials Japan Co., Ltd. (72) Inventor Toshiyuki Tsukamoto 14-3 Shinizumi, Narita-shi, Chiba Applied Materials Japan Co., Ltd. F-term (reference) 5F045 AA20 AB32 AC11 AD14 AE23 AF03 BB02 BB03 BB08 DP04 DP21 DP28 EB08 EB11 EB12 EB15 EK12 EK25 EM10 EN04 HA22

Claims (7)

[Claims] A substrate support member installed in the processing chamber and supporting a substrate to be processed;
A substrate heating method in a semiconductor manufacturing apparatus that performs a heat treatment on the substrate to be processed supported by the substrate support member, wherein a substrate preparing step includes preparing a plurality of substrates to be processed at predetermined positions outside the processing chamber. A pre-heating step of pre-heating the processing chamber in advance; and sequentially transferring the plurality of substrates to be processed one by one into the processing chamber pre-heated in the pre-heating step, and supporting the substrates by the substrate support member. And a heat treatment step of performing a heat treatment respectively. 2. The substrate heating method according to claim 1, wherein said preheating step is performed simultaneously with said substrate preparing step. 3. The substrate heating method according to claim 1, wherein in the preheating step, a temperature of the preheating is set lower than a temperature of the heat treatment in the heat treatment step. 4. An atmosphere in the processing chamber when performing the preheating in the preheating step,
N _2, H ₂ or the substrate heating method according to claim 1, wherein a gas atmosphere containing at least one of O _2,. 5. The substrate heating method according to claim 1, wherein in the preheating step, the time for performing the preheating is 3 minutes or more. 6. The substrate heating method according to claim 1, wherein said preheating in said preheating step and said heat treatment in said heat treatment step are performed using the same heating means. 7. The substrate heating method according to claim 1, wherein in the preliminary heating step, the preliminary heating is performed in a state where the preliminary substrate for the preliminary heating is supported by the substrate supporting member.