JP2005069726A - Method for evaluating organometal compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for evaluating the characteristics of an organometal compound in an actual use and the reactivity, thermal stability and pyrolyzing characteristics in an environment wherein the organometal compound and a reaction gas are allowed to coexist directly. <P>SOLUTION: In this method for evaluating the organometal compound, an organometal compound raw material for use in forming a membrane by chemical vapor deposition is evaluated by a differential scanning calorimetric method. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００３７】
【表２】

【００３８】
【表３】

【００３９】
表１〜表３より明らかなように、使用した反応ガスの種類によって膜厚に若干のばらつきはみられるが、化合物Ａ、化合物Ｅ及び化合物Ｆが成膜速度が高く、化合物Ｊは成膜速度が低い傾向を示す結果となった。この表１の結果は前述した実施例１〜１１の図９に示す検量線に対応し、表２の結果は前述した実施例１２〜２２の図１０に示す検量線に対応し、表３の結果は前述した実施例２３〜３３の図１１に示す検量線にそれぞれ対応している。この結果から本発明の評価方法は、実際の薄膜形成環境における、有機金属化合物と反応ガスとを直接的に共存させた環境での反応性、熱的安定性、熱分解特性を評価することができていることが判った。
【００４０】
【発明の効果】
以上述べたように、本発明の有機金属化合物の評価方法は、化学蒸着によって薄膜を形成するための有機金属化合物原料を示差走査熱量測定法によって評価することを特徴とする。有機金属化合物の実際の用途における特性を評価することができる。具体的には、上記工程（ａ）〜工程（ｎ）を経ることにより、有機金属化合物と反応ガスとを直接的に共存させた環境での反応性、熱的安定性及び熱分解特性を評価することができる。
【図面の簡単な説明】
【図１】本発明の評価方法における工程（ａ）〜工程（ｆ）を示すフロー図。
【図２】本発明の評価方法における工程（ｇ）〜工程（ｎ）を示すフロー図。
【図３】有機金属化合物と反応ガスを所定の割合で封入した密閉容器の断面構成図。
【図４】本実施の形態における２つのピーク点ａ，ｂを有し、かつピークの山が重なり合った第１曲線を示す図。
【図５】実施例１における封入割合を０％としたときのＤＳＣ曲線を示す図。
【図６】実施例１における封入割合を５％としたときのＤＳＣ曲線を示す図。
【図７】実施例１における封入割合を１５％としたときのＤＳＣ曲線を示す図。
【図８】実施例１における封入割合を３５％としたときのＤＳＣ曲線を示す図。
【図９】実施例１〜１１における化合物Ａ〜Ｋの検量線を示す図。
【図１０】実施例１２〜２２における化合物Ａ〜Ｋの検量線を示す図。
【図１１】実施例２３〜３３における化合物Ａ〜Ｋの検量線を示す図。
【図１２】ＭＯＣＶＤ装置の概略図。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dielectric film such as a FeRAM (Ferroelectric Random Access Memory) and a DRAM (Dynamic Random Access Memory), a complex oxide dielectric thin film used for a dielectric filter, and a barrier film of a semiconductor device. Further, the present invention relates to a method for evaluating an organometallic compound suitable as a raw material for forming an oxide film for a ferroelectric material by a metal organic chemical vapor deposition (hereinafter referred to as MOCVD method) or a liquid phase growth method. . More specifically, the present invention relates to a method for evaluating an organometallic compound using a differential scanning calorimetry (hereinafter referred to as DSC method).
[0002]
[Prior art]
Conventionally, as a method for evaluating the physical properties of an organometallic compound that is a raw material for forming a thin film, a method for measuring a vaporization rate or the like of an organometallic compound by using a thermogravimetry (hereinafter referred to as TG) method is known. ing. For example, the synthesized organometallic compound is evaluated for characteristics such as vaporization and thermal stability of the organometallic compound by a TG method (see, for example, Patent Document 1). As in the evaluation method shown in Patent Document 1, by measuring the organometallic compound by the TG method, the TG loss on the low temperature side of the organometallic compound, the impurity metal content contained in the organometallic compound, and the like are evaluated. be able to. The TG method is a technique for measuring the mass of a substance as a function of temperature while changing the temperature of the substance according to a controlled program. In the TG measurement method for an organometallic compound, a measurement container containing an organometallic compound is heated with a predetermined temperature profile, and a change in weight due to the heating temperature of the organometallic compound in the measurement container is measured. Conventionally, in the evaluation of organometallic compounds by the TG method, the organometallic compound is gradually vaporized by heating to reduce its weight, and a compound with less residue remaining in the measurement container at the end of measurement is used for thin film formation. In many cases, the raw materials were evaluated as having excellent thermal stability, vaporization characteristics, purity, and the like.
[0003]
On the other hand, the present inventors have repeatedly conducted various thin film formation experiments using commercially available organometallic compound raw materials. Depending on the raw materials, even if the raw materials exhibit a good vaporization rate by the TG method, Insufficient film formation speed and uniformity of the composite metal oxide thin film composition formed, and clogging of the raw material supply pump. I found out.
Therefore, the present inventors have evaluated the organometallic compound for forming a thin film by chemical vapor deposition, using a gas chromatograph-mass spectrometry (hereinafter referred to as GC-MS) method. (For example, refer to Patent Document 2). By measuring the organometallic compound disclosed in Patent Document 2 by the GC-MS method and determining that the proportion of the organometallic compound monomer is 80% by weight or more of the raw material, the raw material is The film formation stability of the raw material for forming a thin film for each batch was appropriately evaluated.
[0004]
[Patent Document 1]
JP 2003-81908 A (paragraph
Etc.)
[Patent Document 2]
JP-A-10-282081 (
Claims 1 and
(Claim 2))
[0005]
[Problems to be solved by the invention]
However, the evaluation by the TG method shown in the above-mentioned Patent Document 1 and the evaluation by the GC-MS method shown in the above-mentioned Patent Document 2 are different from the thin film formation conditions in the case of actually forming a thin film using an organometallic compound. It was measured and evaluated in the environment. Therefore, the evaluated vaporization and thermal stability are not necessarily effective stability evaluations when a thin film is actually formed using an organometallic compound.
[0006]
The objective of this invention is providing the evaluation method of the organometallic compound which can evaluate the characteristic in the actual use of an organometallic compound.
Another object of the present invention is to provide an organometallic compound evaluation method capable of evaluating reactivity, thermal stability, and thermal decomposition characteristics in an environment in which an organometallic compound and a reactive gas coexist directly. It is in.
[0007]
[Means for Solving the Problems]
The invention according to claim 1 is an organometallic compound evaluation method characterized in that an organometallic compound raw material for forming a thin film by chemical vapor deposition is evaluated by differential scanning calorimetry.
In the invention which concerns on Claim 1, the characteristic combined with the actual use of the organometallic compound can be evaluated.
[0008]
As shown in FIGS. 1 and 2, the invention according to claim 2 includes: (a) a step of sealing the organometallic compound and the reaction gas in a first ratio in a first sealed container; and (b) a first comparison container. A step of encapsulating a known calorific standard substance and an inert gas at a predetermined ratio, and (c) heating the first sealed container and the first comparison container with a predetermined temperature profile in an inert gas atmosphere. (D) a step of measuring the difference between the energy consumed by the first sealed container and the energy consumed by the first comparison container by the differential scanning calorimetry, and (e) creating a first curve from the measurement result. And (f) obtaining a first heat quantity of the organometallic compound enclosed in the first sealed container from an area surrounded by the peak point of the first curve, the transition start point, and the dislocation end point; and (g) the organometallic. The compound and the reaction gas are sealed in the step (a). A step of sealing in a second sealed container at a second ratio different from the one ratio, and (h) a second reference container filled with a calorimetric standard substance and an inert gas with a known calorie at a rate substantially the same as the above step (b). And (i) heating and heating the second sealed container and the second comparison container in an inert gas atmosphere with substantially the same temperature profile as in the above (c) process, and (j) the second sealed container A step of measuring the difference between the energy consumed by the container and the energy consumed by the second comparative container by differential scanning calorimetry, (k) creating a second curve from the measurement result, and (l) a second curve. A step of obtaining the second heat quantity of the organometallic compound enclosed in the second sealed container from the area surrounded by the peak point, the transition start point, and the dislocation end point, (m) the result of the step (f) and the above (l) From the result of the process, to the first heat amount and the second ratio to the first ratio Plotting each second heat quantity to create a calibration curve, and (n) evaluating the reactivity and thermal decomposability of the organometallic compound and the reaction gas from the slope of the created calibration curve. This is a characteristic method for evaluating an organometallic compound.
In the invention according to claim 2, the reactivity, thermal stability, and thermal decomposition in an environment in which the organometallic compound and the reactive gas are directly coexisted through the steps (a) to (n). Properties can be evaluated.
[0009]
The invention according to claim 3 is the invention according to claim 2, wherein (o) the first ratio in which the organometallic compound and the reaction gas are encapsulated in the step (a) and the first ratio in the step (g) are encapsulated. The evaluation method further includes a step of changing the step (g) to the step (l) one or more times by changing to a proportion different from the two proportions.
In the invention which concerns on Claim 3, the calibration curve of a more highly accurate organometallic compound and reaction gas is obtained by further including the said process (o).
[0010]
The invention according to claim 4 is the invention according to claim 2 or 3, wherein the metal contained in the organometallic compound is composed of Zr, Hf, Si, Ti, Ta, V, Cu, Pr, Pb and Y. It is the evaluation method which is 1 type, or 2 or more types selected more.
The invention according to claim 5 is the invention according to claim 2 or 3, wherein the reaction gas is O. ₂ , O ₃ , Air, NH ₃ Gas, H ₂ N-NH ₂ , Water vapor and H ₂ O ₂ It is the evaluation method containing 1 or 2 or more gas selected from the group which consists of.
The invention according to claim 6 is the invention according to claim 2, wherein the sealing ratio of the organometallic compound and the reaction gas is in the range of 5 to 90% by volume ratio (reaction gas / organometallic compound). It is.
The invention according to claim 7 is the evaluation method according to claim 2, wherein the temperature profile is a temperature rising rate of 2 to 10 ° C./min and a temperature range of room temperature to 600 ° C.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
Usually, when a thin film is formed using an organometallic compound, an organic metal compound gas and O are placed in a deposition chamber 10 provided in a deposition apparatus as shown in FIG. ₂ , H ₂ , NH ₃ These reaction gases are supplied. The film forming chamber 10 is heated to a predetermined temperature, and the organometallic compound gas and the reaction gas undergo thermal decomposition in the state where they coexist, thereby forming a desired thin film on the surface of the substrate 13 or the like. Therefore, even if the thermal stability, vaporization characteristics, purity, etc. of the organometallic compound itself are measured by the TG method, it is merely an assessment of the organometallic compound itself, and the evaluation of the organometallic compound as a raw material for forming a thin film. Is not directly connected. That is, when evaluating an organometallic compound as a raw material for forming a thin film, effective evaluation cannot be performed unless measurement is performed in an environment coexisting with a reaction gas to be actually reacted.
[0012]
The inventor of the present invention encloses an organometallic compound and a reaction gas at a predetermined ratio in a measurement vessel of a DSC apparatus because an organic metal compound that easily exhibits reactive decomposition tends to generate a decomposition product in a trace amount of reaction gas atmosphere. DSC measurement was performed, and this encapsulation ratio was changed to various ratios and repeated DSC measurement was performed. As a result, a linear proportional line between the peak area of the DSC curve, the sample amount, and the reaction gas amount was obtained depending on different encapsulation ratios. It was found that the relationship was obtained, and that the greater the slope of this straight line, the better the decomposition characteristics and the better the correlation of the film formation rate. The DSC method is a method for measuring physical properties such as a heat capacity and a melting point of a measurement sample, and an enthalpy change associated with a thermal change such as phase transition, melting, and reaction. In general, it is used as a one-dimensional evaluation method for examining information specific heat capacity, heat of evaporation, etc. of endothermic, exothermic and phase transition points of organic and inorganic substances. As a measuring method, a measurement sample and a reference substance are put in separate sealed containers, and heated or cooled at a constant rate at the same time, and a temperature difference between the two substances at that time is measured. In normal DSC measurement, air gap filling is used in which a measurement sample is placed in a sealed container in an atmosphere of an inert gas such as air or nitrogen or argon, and the sealed container is sealed.
[0013]
In the present invention, a reaction gas is filled in a space in a sealed container and several kinds of measurement samples are prepared by enclosing at a plurality of enclosing ratios, and a change in the shape of the organometallic compound due to heating of the reaction gas and the measurement sample present in the space is measured by the DSC method. The reaction and decomposition were replaced with a device such as a CVD reactor or a vaporizer, which was newly adopted as a method for finding the reaction. Using this method, the decomposition temperature due to the direct reaction between the gas and the sample can be found on the monitor. Moreover, the idea of heating together these reaction gas and the organometallic compound which is a thin film forming raw material, and evaluating the thin film forming raw material has not been performed at all yet.
[0014]
The present invention has been completed based on such findings. That is, the organometallic compound evaluation method of the present invention is characterized in that an organometallic compound raw material for forming a thin film by chemical vapor deposition is evaluated by a differential scanning calorimetry method. With the evaluation method of the present invention, it is possible to evaluate the characteristics combined with the actual use of the organometallic compound.
[0015]
A specific evaluation method will be described below with reference to FIGS.
First, as shown in FIG. 1, an organometallic compound and a reaction gas are sealed in a first sealed container at a first ratio (step (a)). As the metal contained in the organometallic compound in the present invention, one or more selected from the group consisting of Zr, Hf, Si, Ti, Ta, V, Cu, Pr, Pb and Y are selected. The coordination compound coordinated to these metals and the number of coordination thereof are not particularly limited, and any of the conventionally known coordination compounds can be used as long as it is an organometallic compound in which one or more coordination compounds are coordinated. It can be a measurement object in the evaluation method of the invention. As the reaction gas, O ₂ , O ₃ , Air, NH ₃ Gas, H ₂ N-NH ₂ , Water vapor and H ₂ O ₂ And a gas containing one or more gases selected from the group consisting of: The reaction gas is preferably selected according to the use of the organometallic compound to be measured. That is, for example, when the thin film to be formed is an oxide film, the reaction gas is O ₂ , O ₃ When the thin film to be formed is a nitride film, the reaction gas is air, NH, etc. ₃ Gas, H ₂ N-NH ₂ Etc. are selected. As shown in FIG. 3, the first sealed container may have a structure in which a thin upper lid 2 is fixed to a container 1 used for general DSC measurement to form a sealed container 3. Examples of the material of the container include SUS316L and SUS304. In addition, the code | symbol 4 shown in FIG. 3 shows an organometallic compound, and the code | symbol 5 shows reaction gas, respectively. The sealing ratio of the organometallic compound and the reaction gas is selected in a range of 5 to 90% in terms of volume ratio (reaction gas / organometallic compound). When the volume ratio is less than 5%, significant oxidation occurs, and when the volume ratio exceeds 90%, an error on the apparatus occurs. The volume of the encapsulated organometallic compound is calculated from the specific gravity and weight of the organometallic compound.
[0016]
Next, returning to FIG. 1, a calorific standard substance and an inert gas having a known calorific value are sealed in the first comparison container at a predetermined ratio (step (b)). Indium (In) is preferred as the calorie standard material with a known calorific value. The enclosure ratio is the same as the reaction gas and organometallic compound enclosed in the first sealed container. A rare gas such as nitrogen or argon is selected as the inert gas. It is preferable to use the first comparison container having the same structure and the same material as the first sealed container.
Next, the first sealed container and the first comparison container are heated with a predetermined temperature profile in an inert gas atmosphere (step (c)). The temperature profile is defined by a temperature increase rate of 2 to 10 ° C./min and a temperature range of room temperature to 600 ° C. When the rate of temperature rise is less than 2 ° C./min, significant oxidation occurs, and when it exceeds 10 ° C./min, there is a problem of excessive thermal decomposition. A preferable temperature increase rate is 5 to 10 ° C./min. Although the measurement temperature range may exceed 600 ° C., since a general organometallic compound decomposes at 600 ° C. or less, the above measurement temperature is set as the upper limit.
[0017]
Next, the difference between the energy consumed by the first sealed container and the energy consumed by the first comparison container is measured by the differential scanning calorimetry, and a first curve is created from the measurement result (step (d) and step ( e)).
The first calorific value of the organometallic compound sealed in the first sealed container is determined from the area surrounded by the peak point, the transition start point, and the dislocation end point of the obtained first curve (step (f)). The first heat quantity consumed by the organometallic compound measured by the area surrounded by the first curve and the base line connecting the lowest transition start point and the dislocation end point shown in the first curve obtained. is there. For example, when a DSC curve having two peak points a and b as shown in FIG. 4 as the first curve and overlapping peak peaks is obtained, the lowest transition start point and dislocation end indicated by the curve are obtained. The sum of the area A and the area B surrounded by the baseline C connecting the two points and the DSC curve is the apparent total calorific value consumed by the measured organometallic compound. The area of the area B where the mountains overlap is drawn by drawing a straight line bC from the peak point B to the base line C so that the slope is almost the same as the slope from the peak point b to the vicinity of the transition end point. The area surrounded by the straight line bC and the DSC curve is defined as area B. Similarly, the area of the area A where the mountains overlap is drawn with a straight line Ca from the base line C to the peak point a so that the slope is almost the same as the slope from the vicinity of the transition start point to the peak point a. An area surrounded by the line C, the straight line Ca, and the DSC curve is defined as an area A. In the case of the DSC curve shown in FIG. 4, the area to be evaluated by the evaluation method of the present invention is area B, and the area B tends to increase as the ratio of the reaction gas to be sealed increases.
[0018]
Subsequently, as shown in FIG. 2, the organometallic compound and the reaction gas are sealed in the second sealed container at a second rate different from the first rate sealed in the step (a) (step (g)). The second encapsulation ratio is set to be a ratio different from the first encapsulation ratio described above. For example, when the first enclosure ratio is set to 20% by volume, the second enclosure ratio is set to a ratio greatly different from the first enclosure ratio, such as 60%, and the calibration in the subsequent step (m) is performed. This makes it easier to create lines.
Next, a calorific standard substance having a known calorific value and an inert gas are sealed in the second comparison container at a rate substantially the same as that in the step (b) (step (h)). As the second comparison container, the first comparison container may be used as it is.
[0019]
Next, the second sealed container and the second comparison container are heated and heated in an inert gas atmosphere with substantially the same temperature profile as in step (c) (step (i)). The reason why the temperature profile is substantially the same as that in the step (c) is to reduce the measurement error.
Next, the difference between the energy consumed by the second sealed container and the energy consumed by the second comparison container is measured by differential scanning calorimetry, and a second curve is created from the measurement result (step (j) and step ( k)).
The second heat quantity of the organometallic compound enclosed in the second sealed container is determined from the area surrounded by the peak point, the transition start point, and the dislocation end point of the obtained second curve (step (l)). In this step, the second heat quantity is obtained by the same method as the method for obtaining the first heat quantity in the step (f).
[0020]
In addition, as the step (o), the sealing ratio of the organometallic compound and the reaction gas is changed to a ratio different from the first ratio sealed in the step (a) and the second ratio sealed in the step (g) (g). The step of repeating the step (l) 1 or 2 or more may be further included. By further including the step (o), the number of plots in the subsequent step (m) increases, so that a more accurate calibration curve between the organometallic compound and the reaction gas can be obtained.
[0021]
From the result of the step (f) and the result of the step (l), the first heat amount with respect to the first rate and the second heat amount with respect to the second rate are plotted to create a calibration curve (step (m)). The first and second calories are plotted with the calorific value obtained by dividing the calorific value as the area area by the weight of the organometallic compound sample / sample on the vertical axis and the volume ratio of the enclosing ratio on the horizontal axis. A calibration curve is created from these two plots.
Finally, the reactivity and thermal decomposability between the organometallic compound and the reactive gas are evaluated from the slope of the prepared calibration curve (step (n)). When the slope of the calibration curve is large, the deposition rate is high and the low-temperature decomposability tends to be high. On the contrary, when the slope of the calibration curve is small, the film formation rate is low and the low-temperature decomposability tends to be low.
[0022]
As described above, the steps (a) to (n) of the present invention are further passed through the step (o), so that the reactivity, thermal stability, and thermal decomposition in an environment in which the organometallic compound and the reactive gas coexist are present. The characteristics can be clearly evaluated. Various types of organometallic compounds and reaction gas types can be changed or combined to create multiple types of calibration curves, and the slope of each calibration curve can be examined. It is possible to clearly evaluate whether thermal stability and thermal decomposition characteristics are good.
[0023]
【Example】
Next, examples of the present invention will be described in detail together with comparative examples.
<Example 1>
First, Hf (dimethylamide) as an organometallic compound ₄ (Hereinafter referred to as Compound A) as the reactive gas O ₂ Prepared. Compound A is then converted to N ₂ It put in the container made from SUS under atmosphere, and it enclosed with the airtight container so that the enclosure ratio might be 0% by volume ratio (reaction gas / organometallic compound). In addition, the enclosure ratio of 0% indicates that the air gap of the sealed container is filled with only nitrogen and does not contain oxygen. Next, an SUS thin upper lid was set on the upper part of the container, and a hermetic container was produced by pressing the thin upper lid and the container by pressing from above using a standard press machine which is a DSC sample production kit. Similarly, the ratio of the organometallic compound and the reactive gas is changed so that the enclosing ratio is 5%, 15% and 35% in the volume ratio (reactive gas / organometallic compound), and the total 4 kinds are enclosed in the container. An airtight container was prepared. Next, In is prepared as a calorimetric standard substance, and In and N are prepared in a comparison container. ₂ Gas was sealed at a predetermined ratio to prepare a comparative container. Next, the sealed container and the comparative container are set in the measuring furnace of the DSC apparatus (DSC6200R; manufactured by Seiko Instruments Inc.), respectively, and the temperature profile is measured at a temperature rising rate of 10 ° C./min. The heating measurement was carried out with setting. The flow gas in the measurement furnace of the DSC apparatus was Ar, and the flow rate was set to 50 ml / min. Measurements were performed under the same conditions for sealed containers sealed at different sealing ratios, and four DSC curves were obtained. FIG. 5 shows a DSC curve when the encapsulation rate is 0%, FIG. 6 shows a DSC curve when the encapsulation rate is 5%, FIG. 7 shows a DSC curve when the encapsulation rate is 15%, and FIG. Each DSC curve is shown.
[0024]
<Example 2>
Si (dimethylamide) instead of compound A ₄ (Hereinafter referred to as Compound B), and DSC measurement was performed in the same manner as in Example 1 except that the encapsulation ratio was 0%, 40%, 75%, and 95%.
<Example 3>
V (methylcyclopentadienide) instead of compound A ₂ (Hereinafter referred to as Compound C), and DSC measurement was performed in the same manner as in Example 1 except that the encapsulation ratio was 0%, 40%, and 63%.
<Example 4>
Ta (methylcyclopentadienide) instead of compound A ₂ H ₃ (Hereinafter referred to as Compound D), and DSC measurement was performed in the same manner as in Example 1 except that the encapsulation ratio was 0%, 55%, 79%, and 100%.
[0025]
<Example 5>
Ti (iPrO) instead of Compound A ₂ (DPM) ₂ (Hereinafter referred to as Compound E), and DSC measurement was performed in the same manner as in Example 1 except that the encapsulation ratio was 0%, 18%, 38%, and 60%.
<Example 6>
W (CO) instead of Compound A ₅ (Hereinafter referred to as Compound F), and DSC measurement was performed in the same manner as in Example 1 except that the encapsulation ratio was 0%, 30%, 41%, and 70%.
<Example 7>
Al (iBuO) instead of compound A ₃ (Hereinafter referred to as Compound G), and DSC measurement was performed in the same manner as in Example 1 except that the encapsulation ratio was 0%, 55%, 79%, and 100%.
[0026]
<Example 8>
Zr (diethylamide) instead of compound A ₄ (Hereinafter referred to as Compound H), and DSC measurement was performed in the same manner as in Example 1 except that the encapsulation ratio was 0%, 45%, 73%, and 97%.
<Example 9>
Nb (diethylamide) instead of compound A ₄ (Hereinafter referred to as Compound I), and DSC measurement was performed in the same manner as in Example 1 except that the encapsulation ratio was 0%, 58%, 85%, and 110%.
<Example 10>
Pr (acetylacetonate) instead of compound A ₃ (Hereinafter referred to as Compound J), and DSC measurement was performed in the same manner as in Example 1 except that the encapsulation ratio was 0%, 10%, 80%, and 105%.
<Example 11>
DSC was used in the same manner as in Example 1 except that Cu (atms) (hfac) (hereinafter referred to as Compound K) was used instead of Compound A, and the encapsulation ratio was changed to 0%, 28%, 60% and 87%. Measurements were made.
[0027]
<Example 12>
React gas as O ₂ NH from gas ₃ DSC measurement was performed in the same manner as in Example 1 except that the gas was used.
<Example 13>
React gas as O ₂ NH from gas ₃ DSC measurement was performed in the same manner as in Example 2 except that the sealing ratio was changed to 0%, 42%, 60%, and 85% instead of gas.
<Example 14>
React gas is O ₂ NH from gas ₃ DSC measurement was performed in the same manner as in Example 3 except that the sealing ratio was changed to 0%, 20%, 40%, and 60% instead of gas.
<Example 15>
React gas as O ₂ NH from gas ₃ DSC measurement was performed in the same manner as in Example 4 except that the gas was used.
[0028]
<Example 16>
React gas as O ₂ NH from gas ₃ DSC measurement was performed in the same manner as in Example 5 except that the sealing ratio was changed to 0%, 21%, 45%, and 63% instead of gas.
<Example 17>
React gas as O ₂ NH from gas ₃ DSC measurement was performed in the same manner as in Example 6 except that the sealing ratio was changed to 0%, 35%, 48%, and 70% instead of gas.
<Example 18>
React gas as O ₂ NH from gas ₃ DSC measurement was performed in the same manner as in Example 7 except that the sealing ratio was changed to 0%, 40%, 63%, and 93% instead of gas.
<Example 19>
React gas as O ₂ NH from gas ₃ DSC measurement was performed in the same manner as in Example 8 except that the sealing ratio was changed to 0%, 50%, 78%, and 98% instead of gas.
[0029]
<Example 20>
React gas as O ₂ NH from gas ₃ DSC measurement was performed in the same manner as in Example 9 except that the sealing ratio was changed to 0%, 55%, and 83% instead of gas.
<Example 21>
React gas as O ₂ NH from gas ₃ DSC measurement was performed in the same manner as in Example 10 except that the sealing ratio was changed to 0%, 10%, 76%, and 105% instead of gas.
<Example 22>
React gas is O ₂ NH from gas ₃ DSC measurement was performed in the same manner as in Example 11 except that the sealing ratio was changed to 0%, 28%, 60%, and 85% instead of gas.
[0030]
<Example 23>
React gas is O ₂ DSC measurement was performed in the same manner as in Example 1 except that the gas was changed to water vapor (water).
<Example 24>
React gas is O ₂ DSC measurements were performed in the same manner as in Example 2 except that the gas was replaced with water vapor (water) and the encapsulation ratio was changed to 0%, 42%, 75%, and 90%.
<Example 25>
React gas is O ₂ DSC measurement was performed in the same manner as in Example 3, except that the gas was replaced with water vapor (water) and the encapsulation ratio was changed to 0%, 20%, 40%, and 60%.
<Example 26>
React gas is O ₂ DSC measurement was performed in the same manner as in Example 4 except that the gas was replaced with water vapor (water).
[0031]
<Example 27>
React gas is O ₂ DSC measurement was performed in the same manner as in Example 5 except that the gas was replaced with water vapor (water) and the encapsulation ratio was 0%, 20%, 43%, and 65%.
<Example 28>
React gas is O ₂ DSC measurement was performed in the same manner as in Example 6 except that the gas was replaced with water vapor (water) and the encapsulation ratio was changed to 0%, 36%, 44%, and 70%.
<Example 29>
React gas is O ₂ DSC measurement was performed in the same manner as in Example 7 except that the gas was replaced with water vapor (water) and the encapsulation ratio was 0%, 40%, 65%, and 95%.
<Example 30>
React gas is O ₂ DSC measurement was performed in the same manner as in Example 8 except that the gas was replaced with water vapor (water) and the encapsulation ratio was changed to 0%, 54%, 78%, and 95%.
[0032]
<Example 31>
React gas is O ₂ DSC measurements were performed in the same manner as in Example 9 except that the gas was replaced with water vapor (water) and the encapsulation ratio was changed to 0%, 45%, 70%, and 85%.
<Example 32>
React gas is O ₂ DSC measurement was performed in the same manner as in Example 10 except that the gas was replaced with water vapor (water) and the encapsulation ratio was 0%, 10%, 58%, and 110%.
<Example 33>
React gas is O ₂ DSC measurement was performed in the same manner as in Example 11 except that the gas was replaced with water vapor (water) and the encapsulation ratio was 0%, 25%, 58%, and 85%.
[0033]
<Evaluation 1>
Each calorific value obtained from the DSC curve obtained in each of Examples 1 to 11 was obtained, and each calorific value was plotted for each ratio of the organometallic compound and the reaction gas to prepare a calibration curve. Similarly, the amounts of heat obtained from the DSC curves obtained in Example 12 to Example 22 and Example 23 to Example 33 were determined, and each amount of heat was plotted for each proportion of the organometallic compound and the reaction gas. A calibration curve was created. FIG. 9 shows calibration curves in Examples 1 to 11, FIG. 10 shows calibration curves in Examples 12 to 22, and FIG. 11 shows calibration curves in Examples 23 to 33, respectively.
[0034]
As is clear from FIGS. 9 to 11, compounds having a large inclination, that is, a film forming rate and a tendency to have a high low temperature decomposability were Compound A, Compound E, and Compound F. Further, J was a compound having a small inclination, that is, a low film formation rate and a low-temperature decomposability. 9 to 11, the above-mentioned tendency is observed even when different reaction gases are sealed, and the slope of the calibration curve is slightly different depending on the reaction gas even if the type of the organometallic compound is the same. I found out.
[0035]
<Evaluation 2>
The following tests were performed using organometallic compounds A to K.
First, the surface of the substrate is 5000 mm thick SiO ₂ Four Si substrates on each of which were formed were prepared, and the substrates were placed in the film formation chamber of the MOCVD apparatus shown in FIG. Subsequently, the substrate temperature was set to 250 ° C., the vaporization temperature was set to 80 ° C., and the pressure was set to about 665 Pa (5 torr). O as reaction gas ₂ Gas, NH ₃ Gas and water vapor were used, respectively, and the partial pressure was 500 ccm. Next, He gas is used as a carrier gas, and an organometallic compound is supplied at a rate of 0.01 cc / min. When the film formation time is 1 minute, 5 minutes, 10 minutes, and 20 minutes, one sheet each. Each film was taken out from the film formation chamber, and the film thickness of the thin film on the substrate after film formation was measured from a cross-sectional SEM (scanning electron microscope) image. The obtained film thickness results per film formation time are shown in Tables 1 to 3, respectively.
[0036]
[Table 1]

[0037]
[Table 2]

[0038]
[Table 3]

[0039]
As is clear from Tables 1 to 3, although the film thickness varies slightly depending on the type of reaction gas used, Compound A, Compound E and Compound F have high film formation rates, and Compound J has a film formation rate. The result showed a low tendency. The results of Table 1 correspond to the calibration curves shown in FIG. 9 of Examples 1 to 11 described above, and the results of Table 2 correspond to the calibration curves shown in FIG. 10 of Examples 12 to 22 described above. The results correspond to the calibration curves shown in FIG. 11 of Examples 23 to 33 described above. From this result, the evaluation method of the present invention can evaluate reactivity, thermal stability, and thermal decomposition characteristics in an environment where an organometallic compound and a reactive gas coexist directly in an actual thin film formation environment. It turned out that it was made.
[0040]
【The invention's effect】
As described above, the organometallic compound evaluation method of the present invention is characterized in that an organometallic compound raw material for forming a thin film by chemical vapor deposition is evaluated by a differential scanning calorimetry method. The properties of the organometallic compound in the actual application can be evaluated. Specifically, through the steps (a) to (n), the reactivity, thermal stability and thermal decomposition characteristics in an environment in which the organometallic compound and the reactive gas coexist directly are evaluated. can do.
[Brief description of the drawings]
FIG. 1 is a flowchart showing steps (a) to (f) in an evaluation method of the present invention.
FIG. 2 is a flowchart showing steps (g) to (n) in the evaluation method of the present invention.
FIG. 3 is a cross-sectional configuration diagram of a sealed container in which an organometallic compound and a reaction gas are sealed at a predetermined ratio.
FIG. 4 is a diagram showing a first curve having two peak points a and b and overlapping peak peaks in the present embodiment.
5 is a diagram showing a DSC curve when the encapsulation rate in Example 1 is 0%. FIG.
6 is a diagram showing a DSC curve when the encapsulation ratio in Example 1 is 5%. FIG.
FIG. 7 is a diagram showing a DSC curve when the encapsulation rate in Example 1 is 15%.
FIG. 8 is a diagram showing a DSC curve when the encapsulation rate in Example 1 is 35%.
FIG. 9 is a graph showing calibration curves of compounds A to K in Examples 1 to 11.
FIG. 10 is a calibration curve of compounds A to K in Examples 12 to 22.
FIG. 11 shows a calibration curve of compounds A to K in Examples 23 to 33.
FIG. 12 is a schematic view of an MOCVD apparatus.

Claims (7)

An organic metal compound evaluation method for evaluating an organic metal compound raw material for forming a thin film by chemical vapor deposition by a differential scanning calorimetry method. (A) enclosing the organometallic compound and the reaction gas in a first ratio in a first sealed container;
(B) a step of enclosing a calorific standard substance and an inert gas having a known calorific value in a first comparison container at a predetermined ratio;
(C) heating and heating the first sealed container and the first comparison container under a predetermined temperature profile in an inert gas atmosphere;
(D) measuring the difference between the energy consumed by the first sealed container and the energy consumed by the first comparison container by a differential scanning calorimetry method;
(E) creating a first curve from the measurement results;
(F) obtaining a first heat quantity of the organometallic compound enclosed in the first sealed container from an area surrounded by a peak point of the first curve, a transition start point, and a dislocation end point;
(G) encapsulating the organometallic compound and the reaction gas in the second sealed container at a second ratio different from the first ratio encapsulated in the step (a);
(H) a step of encapsulating a calorific standard substance and an inert gas having a known calorific value in a second comparison container at a rate substantially the same as the step (b);
(I) heating and heating the second sealed container and the second comparison container in an inert gas atmosphere with substantially the same temperature profile as in the step (c);
(J) measuring the difference between the energy consumed by the second sealed container and the energy consumed by the second comparison container by a differential scanning calorimetry method;
(K) creating a second curve from the measurement result;
(L) obtaining a second heat quantity of the organometallic compound sealed in the second sealed container from an area surrounded by a peak point, a transition start point and a dislocation end point of the second curve;
(M) From the result of the step (f) and the result of the step (l), plotting the first heat quantity with respect to the first ratio and the second heat quantity with respect to the second ratio to create a calibration curve;
(N) A method for evaluating the organometallic compound, comprising evaluating the reactivity and thermal decomposability between the organometallic compound and the reactive gas from the slope of the prepared calibration curve. (O) Step (g) to step described above are performed by changing the enclosure ratio of the organometallic compound and the reaction gas to a ratio different from the first ratio enclosed in the step (a) and the second ratio enclosed in the step (g). (L) The evaluation method according to claim 2, further comprising a step of repeating the step one or more times. The metal according to claim 2 or 3, wherein the metal contained in the organometallic compound is one or more selected from the group consisting of Zr, Hf, Si, Ti, Ta, V, Cu, Pr, Pb and Y. Method. The reaction gases _O 2, _{O 3,} air, NH _{3 gas,} H ₂ N-NH _2, according to claim 2 or 3, wherein including one or more gas selected from the group consisting of water vapor and _H 2 _{O 2} Evaluation methods. The evaluation method according to claim 2, wherein an encapsulation ratio of the organometallic compound and the reaction gas is in the range of 5 to 90% in terms of volume ratio (reaction gas / organometallic compound). The evaluation method according to claim 2, wherein the temperature profile is a temperature increase rate of 2 to 10 ° C / min and a temperature range of room temperature to 600 ° C.

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