JPH0897206A - Forming method of thermal oxidation film - Google Patents
Forming method of thermal oxidation filmInfo
- Publication number
- JPH0897206A JPH0897206A JP23393394A JP23393394A JPH0897206A JP H0897206 A JPH0897206 A JP H0897206A JP 23393394 A JP23393394 A JP 23393394A JP 23393394 A JP23393394 A JP 23393394A JP H0897206 A JPH0897206 A JP H0897206A
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- Japan
- Prior art keywords
- oxide film
- gas
- substrate
- gas containing
- silicon
- Prior art date
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- Formation Of Insulating Films (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、熱酸化膜形成方法に係
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a thermal oxide film.
【０００２】[0002]
【従来の技術】従来シリコン上に熱酸化膜を形成する場
合、バッチ式の装置を用いて通常行われてきた。しか
し、ウエハの口径が大きくなるにつれて、バッチ式の装
置ではウエハ面内で均一に酸化することが困難になって
いる。しかし、枚葉式の装置でバッチ式の装置と同じ歩
留まりを保つためには、酸化速度を上げる必要がある。2. Description of the Related Art Conventionally, when a thermal oxide film is formed on silicon, it has been usually performed by using a batch type apparatus. However, as the diameter of the wafer becomes larger, it becomes more difficult for the batch type apparatus to uniformly oxidize within the wafer surface. However, in order to maintain the same yield in a single-wafer type device as in a batch type device, it is necessary to increase the oxidation rate.
【０００３】シリコンを高速で酸化する方法として、一
つには高圧酸化がある。これは酸化装置内に数気圧から
十数気圧の酸素や水を導入して熱酸化を行う方法であ
り、この方法によれば、酸化剤の量を増やすことで酸化
速度を上げることはできるが、高温に加熱しながら装置
内を高圧に保持することは、非常に危険であり実用的で
ない。One of the methods for oxidizing silicon at high speed is high-pressure oxidation. This is a method of performing thermal oxidation by introducing oxygen or water of several atmospheres to several tens of atmospheres into the oxidizing device, and according to this method, the oxidation rate can be increased by increasing the amount of the oxidizing agent. It is very dangerous and impractical to keep the inside of the device at a high pressure while heating it to a high temperature.
【０００４】もう一つの高速酸化法として、オゾンやＯ
ラジカルといった活性なガスを用いる方法がある。これ
らのガスは活性で、Ｏ2 やＨ2 Ｏよりもシリコンと速く
反応してシリコン酸化物を形成する。ここで通常、オゾ
ンやＯラジカルは酸化装置と別の領域でＯ2 などのガス
の放電により形成し、酸化装置に導入するが、せいぜい
数％から十数％のガスしかオゾンやＯラジカルにならな
い。これは、放電効率を上げるために放電は減圧で行わ
れるが、これがガスの活性化を妨げているからである。
さらに、放電領域から酸化装置まで輸送される間にオゾ
ンやＯラジカルは、壁と反応したり相互に反応したりし
て失活してしまうと言う事も考えられる。Another high-speed oxidation method is ozone or O.
There is a method of using an active gas such as a radical. These gases are active and react faster with silicon than with O 2 and H 2 O to form silicon oxide. Here, normally, ozone and O radicals are formed by discharge of a gas such as O 2 in a region different from that of the oxidizer and introduced into the oxidizer, but only a few percent to ten and a few percent of the gases become ozone and O radicals. . This is because the discharge is performed under a reduced pressure in order to improve the discharge efficiency, which prevents activation of the gas.
Furthermore, it can be considered that ozone and O radicals are deactivated by reacting with the walls and with each other while being transported from the discharge region to the oxidizer.
【０００５】即ち、酸化装置内の被処理基体に供給でき
るオゾンやＯラジカルの量はかなり少なくなるので、常
圧のＯ2 やＨ2 Ｏ雰囲気化で行う酸化とオゾンやＯラジ
カルを用いた酸化とでは酸化速度にそれほど差がない。That is, since the amounts of ozone and O radicals that can be supplied to the substrate to be treated in the oxidizing device are considerably small, the oxidation carried out under the atmospheric pressure of O 2 or H 2 O and the oxidation using ozone or O radicals. There is not much difference in the oxidation rate between and.
【０００６】また、酸化反応がこれら酸化剤の供給律速
になるため、酸化膜厚はガスの流れに非常に依存し、被
処理基体の面内で酸化膜厚がばらつきやすい。さらに、
放電の際にガスと放電領域の部材が反応したり、活性な
オゾン、Ｏラジカルが輸送される間に輸送管の壁と反応
たりして生じる反応生成物がガス中に混入し、シリコン
酸化膜の汚染物として取り込まれてシリコン酸化膜の電
気特性が低下する問題も生じる。Further, since the oxidation reaction is the rate-determining supply of these oxidizing agents, the oxide film thickness is very dependent on the gas flow, and the oxide film thickness tends to vary within the surface of the substrate to be treated. further,
During the discharge, the reaction product generated by the reaction between the gas and the members in the discharge region or the reaction with the wall of the transport tube while the active ozone and O radicals are transported is mixed in the gas, and the silicon oxide film There is also a problem that the electrical characteristics of the silicon oxide film are deteriorated by being taken in as a contaminant of the above.
【０００７】[0007]
【発明が解決しようとする課題】前述したように、枚葉
式の装置でシリコンを高速に熱酸化するために高圧酸化
やオゾン、Ｏラジカルを用いる方法が検討されてきた。
しかし、前者は安全性の面で問題があり、後者は常圧酸
化と比較して酸化速度がそれ程速くならない、酸化膜厚
が被処理基体面内でばらつきやすい、汚染物が混入する
といった問題があった。本発明は上記問題を解決するも
のであり、シリコンを高速にかつ被処理基体の面内を均
一に酸化させる熱酸化膜形成方法を提供することを目的
とする。As described above, methods using high-pressure oxidation, ozone, and O radicals have been studied for high-speed thermal oxidation of silicon in a single-wafer type apparatus.
However, the former has a problem in terms of safety, and the latter has a problem that the oxidation rate is not so fast as compared with atmospheric pressure oxidation, the oxide film thickness tends to vary within the surface of the substrate to be treated, and contaminants are mixed. there were. The present invention solves the above problems, and an object of the present invention is to provide a method for forming a thermal oxide film that oxidizes silicon at a high speed and uniformly within the surface of a substrate to be processed.
【０００８】[0008]
【課題を解決するための手段】上記目的を達成するため
に本発明では、被処理基体を処理容器に収納する工程
と、前記被処理基体の温度を所定の温度に保持すると共
に、前記容器内に酸素原子を含むガスと塩素原子を含む
ガスとを導入する工程と、前記塩素原子を含むガスを励
起する工程と、前記励起した塩素原子を含むガスで前記
酸素原子を含むガスを分解し、前記被処理基体上に熱酸
化膜を形成する工程とを具備した熱酸化膜形成方法を提
供する。In order to achieve the above object, in the present invention, a step of accommodating a substrate to be treated in a treatment container, maintaining the temperature of the substrate to be treated at a predetermined temperature, and A step of introducing a gas containing an oxygen atom and a gas containing a chlorine atom, a step of exciting the gas containing a chlorine atom, and decompose the gas containing an oxygen atom with the gas containing an excited chlorine atom, And a step of forming a thermal oxide film on the substrate to be processed.
【０００９】前記塩素原子を含むガスを励起する工程
は、前記被処理基体の温度を６００℃以上に昇温するこ
と、あるいは、前記容器内に前記被処理基体表面に４５
０ｎｍ以下の波長の光を照射することが望ましい。In the step of exciting the gas containing chlorine atoms, the temperature of the substrate to be treated is raised to 600 ° C. or higher, or 45 is applied to the surface of the substrate to be treated in the container.
It is desirable to irradiate light with a wavelength of 0 nm or less.
【００１０】前記酸素原子を含むガスにはＨ2 Ｏガスを
用いることが望ましい。前記塩素原子を含むガスにはＣ
ｌ2 ガスを用いることが望ましい。前記被処理基体とし
て表面に薄い酸化膜が形成されているものを用いること
が望ましい。前記被処理基体にはシリコン基板を用いる
ことが望ましいIt is desirable to use H 2 O gas as the gas containing oxygen atoms. The gas containing the chlorine atom contains C
It is desirable to use l 2 gas. It is desirable to use a substrate on which a thin oxide film is formed as the substrate to be treated. It is desirable to use a silicon substrate for the substrate to be processed.
【００１１】[0011]
【作用】本発明により、シリコンが高速に酸化される機
構は次のように説明される。第１に、塩素原子を含むガ
ス、例えばＣｌ2 ガスは、約６００℃以上では熱解離し
てＣｌ原子となる。また、Ｃｌ原子は、酸素原子を含む
ガス、例えばＨ2 Ｏガスと衝突するとＨ2 ＯからＨ原子
を引き抜いてＨＣｌとなり、同時にＯＨラジカルを生成
する。さらにこのＯＨラジカル同士が衝突するとＯラジ
カルとＨ2 Ｏが生成する。従って、シリコン表面を６０
０℃以上に加熱してＨ2 Ｏ／Ｃｌ2 ガスに晒すと、シリ
コン表面でＯＨラジカルやＯラジカルが形成し、これら
のラジカルによってシリコンは高速に酸化される。The mechanism of rapid oxidation of silicon according to the present invention will be explained as follows. First, a gas containing chlorine atoms, such as Cl 2 gas, is thermally dissociated into Cl atoms at about 600 ° C. or higher. Further, when Cl atoms collide with a gas containing oxygen atoms, for example, H 2 O gas, H atoms are extracted from H 2 O to become HCl, and at the same time, OH radicals are generated. Further, when the OH radicals collide with each other, O radicals and H 2 O are generated. Therefore, 60
When heated to 0 ° C. or higher and exposed to H 2 O / Cl 2 gas, OH radicals and O radicals are formed on the silicon surface, and these radicals oxidize silicon at high speed.
【００１２】即ち、６００℃より低い温度ではＣｌ2 ガ
スが解離せず、酸化がほとんど進行しない。この状態で
Ｃｌ2 ガスを容器内に導入し、容器内が均一なガスの流
れになった後に６００℃以上に昇温するので、均一な酸
化膜が形成されされる。That is, at a temperature lower than 600 ° C., Cl 2 gas does not dissociate, and oxidation hardly progresses. In this state, Cl 2 gas is introduced into the container, the temperature of the inside of the container is increased to 600 ° C. or more after the uniform gas flow, and a uniform oxide film is formed.
【００１３】第２に、Ｃｌ2 ガスの解離エネルギーは約
４５０ｎｍの光エネルギーに等しい。したがって、それ
よりも波長が短く、エネルギーの高い光をＣｌ2 ガスに
照射するとＣｌ2 が解離してＣｌ原子となる。Ｃｌ原子
はＨ2 Ｏと反応してＨＣｌとＯＨラジカルとを生成し、
ＯＨはまた相互に反応してＯラジカルを生成する。この
ような活性なＯラジカルが表面付近で形成されること及
び光照射による表面励起（シリコン表面で電子やホール
が多数形成される）によりシリコンは高速に酸化され
る。このように本発明を用いることにより、低温かつ短
時間でシリコンを酸化することができた。さらに、Ｃｌ
2 ガスを用いることにより金属汚染物を塩化物として効
果的に除去することができた。Second, the dissociation energy of Cl 2 gas is equal to the light energy of about 450 nm. Therefore, when the Cl 2 gas is irradiated with light having a shorter wavelength and a higher energy, Cl 2 is dissociated into Cl atoms. Cl atoms react with H 2 O to generate HCl and OH radicals,
OH also reacts with each other to generate O radicals. Silicon is rapidly oxidized due to the formation of such active O radicals near the surface and surface excitation by light irradiation (a large number of electrons and holes are formed on the silicon surface). As described above, by using the present invention, it was possible to oxidize silicon at low temperature and in a short time. Furthermore, Cl
It was possible to effectively remove metal contaminants as chlorides by using 2 gases.
【００１４】なお、Ｈ2 Ｏ／Ｃｌ2 ガスを用いて酸化膜
を形成する前に、Ｈ2 Ｏガス中で薄い（約１ｎｍ）酸化
膜を形成することにより、活性なＣｌ原子がシリコンと
直接反応することを防ぐことができた。By forming a thin (about 1 nm) oxide film in H 2 O gas before forming an oxide film using H 2 O / Cl 2 gas, active Cl atoms directly interact with silicon. The reaction could be prevented.
【００１５】このように本発明を用いることで、高速か
つ試料面内で均一に酸化膜を低温で形成することができ
た。また、酸化膜に含まれる金属汚染物を低減すること
ができ、酸化膜の電気的特性が向上した。As described above, by using the present invention, it was possible to form an oxide film at a low temperature at a high speed and uniformly within the surface of the sample. Further, the metal contaminants contained in the oxide film can be reduced, and the electrical characteristics of the oxide film are improved.
【００１６】[0016]
【実施例】以下、本発明の実施例について図面を用いて
詳細に説明する。 実施例１ 本実施例では、Ｈ2 Ｏガス及びＨ2 Ｏ／Ｃｌ2 ガスを用
いたシリコンの熱酸化膜の形成について述べる。Embodiments of the present invention will be described in detail below with reference to the drawings. Example 1 In this example, formation of a thermal oxide film of silicon using H 2 O gas and H 2 O / Cl 2 gas will be described.
【００１７】図１は、本実施例で用いる酸化装置の概略
図である。本装置は、処理容器１１内の試料台１５上に
載置された試料１４をヒータ１６（温度の面内均一性±
０．１％以下）で加熱しながら、ガス導入口１２からガ
スを試料１４に供給、ガス排気口１３から排気して試料
表面に酸化膜を形成するものである。処理容器１１には
石英製の窓１７も備えられており、試料１４に光（照射
強度の面内均一性±０．１％以下）を照射することもで
きる。FIG. 1 is a schematic view of an oxidation device used in this embodiment. This apparatus uses a heater 16 (temperature in-plane uniformity ±) for a sample 14 placed on a sample table 15 in the processing container 11.
While heating at 0.1% or less), gas is supplied to the sample 14 from the gas inlet 12 and exhausted from the gas exhaust port 13 to form an oxide film on the sample surface. The processing container 11 is also provided with a quartz window 17 so that the sample 14 can be irradiated with light (uniformity of irradiation intensity within a plane of ± 0.1% or less).
【００１８】次に、熱酸化膜の形成工程について述べ
る。シリコンウエハをアンモニア水過酸化水素水／水混
合液、硫酸／過酸化水素水混合液、塩酸／過酸化水素水
／水混合液を用いて洗浄し、表面のパーティクルや有機
物、金属汚染物を除去し、さらにこれら洗浄によってシ
リコン表面に形成されたシリコン酸化膜を弗酸を用いて
除去した。このウエハを図１に示した酸化装置の試料台
１５上に載置し、ガス導入口１２からＨ2 Ｏガスを１０
ｌ／ｍｉｎ導入しながら試料１４の温度を５００℃に昇
温した。この処理によりウエハ表面に約１ｎｍの酸化膜
が形成された。Next, the process of forming the thermal oxide film will be described. Silicon wafers are cleaned with ammonia water, hydrogen peroxide solution / water mixture, sulfuric acid / hydrogen peroxide solution, hydrochloric acid / hydrogen peroxide solution / water mixture to remove surface particles, organic substances, and metal contaminants. Then, the silicon oxide film formed on the silicon surface by these cleanings was removed using hydrofluoric acid. This wafer is placed on the sample table 15 of the oxidizing apparatus shown in FIG. 1, and H 2 O gas is supplied from the gas inlet 12 to 10
While introducing 1 / min, the temperature of the sample 14 was raised to 500 ° C. By this treatment, an oxide film of about 1 nm was formed on the wafer surface.
【００１９】次に、ガス導入口１２から導入するガスを
Ｈ2 Ｏ単体からＨ2 Ｏ／Ｃｌ2 混合ガス（Ｈ2 Ｏを１０
ｌ／ｍｉｎ、Ｃｌ2 を２ｌ／ｍｉｎ）に変えた後、試料
の温度を７５０℃に上げ、所定の時間保持した。これに
対し、本発明と比較するために、別の試料では導入する
ガスをＨ2 Ｏのままで、試料の温度を７５０℃に上げ、
所定の時間保持した。Next, the gas introduced from the gas inlet 12 is H 2 O simple substance and H 2 O / Cl 2 mixed gas (H 2 O 10
After changing 1 / min and Cl 2 to 2 l / min), the temperature of the sample was raised to 750 ° C. and kept for a predetermined time. On the other hand, in order to compare with the present invention, in another sample, the gas to be introduced was H 2 O and the temperature of the sample was raised to 750 ° C.
Hold for a predetermined time.
【００２０】熱酸化膜を１０ｎｍ形成するのに必要な時
間を比較したところ、本発明は約１分であったのに対
し、比較例は約３０分であった。本発明で高速にシリコ
ンが酸化される機構は次のように説明される。Ｃｌ2 ガ
スは約６００℃以上では熱解離してＣｌ原子となる。他
方Ｃｌ原子はＨ2 Ｏガスと衝突するとＨ2 ＯからＨ原子
を引き抜いてＨＣｌとなり、同時にＯＨラジカルが生成
する。さらにこのＯＨラジカル同士が衝突するとＯラジ
カルとＨ2 Ｏが生成する。従って、シリコン表面を７５
０℃に加熱してＨ2 Ｏ／Ｃｌ2 ガスに晒すと、シリコン
表面でＯＨラジカルやＯラジカルが形成し、これらのラ
ジカルによってシリコンは高速に酸化される。When the time required to form a thermal oxide film of 10 nm was compared, it was about 1 minute in the present invention, whereas it was about 30 minutes in the comparative example. The mechanism of rapid oxidation of silicon in the present invention is explained as follows. The Cl 2 gas is thermally dissociated into Cl atoms at a temperature of about 600 ° C. or higher. On the other hand, when Cl atoms collide with H 2 O gas, H atoms are extracted from H 2 O to become HCl, and at the same time OH radicals are generated. Further, when the OH radicals collide with each other, O radicals and H 2 O are generated. Therefore, 75
When heated to 0 ° C. and exposed to H 2 O / Cl 2 gas, OH radicals and O radicals are formed on the silicon surface, and silicon is rapidly oxidized by these radicals.
【００２１】また、本発明の方法、即ち５００℃でＨ2
Ｏ／Ｃｌ2 ガスを導入し、その後に８００℃に昇温して
形成したシリコン酸化膜の膜厚のばらつきは±０．５％
以下であったのに対し、比較例の方法、即ちＨ2 Ｏ雰囲
気で７５０℃に昇温し、ガスをＨ2 Ｏ／Ｃｌ2 に切り換
えた直後では試料表面でのガスの流れが不均一であるた
め、７５０℃でＨ2 Ｏ／Ｃｌ2 ガスに切り換えると不均
一な流れの状態で酸化が生じ、形成される酸化膜厚がば
らついてしまう。本発明の方法では、Ｃｌ2 ガスが解離
せず、酸化がほとんど進行しない５００℃でガスを切り
換えるため、不均一なガスの流れによる不均一な酸化は
ほとんど生じず、均一なガスの流れになった後に７５０
℃に昇温されて均一な酸化膜を形成することができる。In addition, the method of the present invention, that is, H 2 at 500 ° C.
The variation in film thickness of the silicon oxide film formed by introducing O / Cl 2 gas and then raising the temperature to 800 ° C. is ± 0.5%
In contrast to the following, the method of the comparative example, that is, immediately after the temperature was raised to 750 ° C. in the H 2 O atmosphere and the gas was switched to H 2 O / Cl 2 , the gas flow on the sample surface was not uniform. Therefore, if the gas is switched to H 2 O / Cl 2 gas at 750 ° C., oxidation occurs in a non-uniform flow state and the formed oxide film thickness varies. In the method of the present invention, the Cl 2 gas is not dissociated and the gas is switched at 500 ° C. at which the oxidation hardly progresses, so that the non-uniform oxidation due to the non-uniform gas flow hardly occurs and the gas flow becomes uniform. After 750
It is possible to form a uniform oxide film by raising the temperature to ° C.
【００２２】さらに、本発明と比較例の方法で形成した
シリコン酸化膜に含まれる金属汚染を調べたところ、前
者は全て金属が１×１０ 9個／ｃｍ2 以下であったのに
対し、後者のいくつかの試料においてはＡｌやＦｅが１
×１０10個／ｃｍ2 検出された。これはＣｌ2 ガスを用
いることにより試料表面及び装置内部の金属汚染が除去
されたためである。Furthermore, when the metal contamination contained in the silicon oxide film formed by the method of the present invention and the method of the comparative example was examined, the former was all less than 1 × 10 9 metal / cm 2 , while the latter was the latter. Al and Fe are 1 in some samples of
× 10 10 pieces / cm 2 was detected. This is because the metal contamination on the sample surface and inside the device was removed by using Cl 2 gas.
【００２３】このように本発明を用いることで、高速か
つ試料面内で均一に酸化膜を形成することができた。ま
た、酸化膜に含まれる金属汚染物を低減することがで
き、酸化膜の電気的特性が向上した。As described above, by using the present invention, the oxide film could be formed at high speed and uniformly within the sample surface. Further, the metal contaminants contained in the oxide film can be reduced, and the electrical characteristics of the oxide film are improved.
【００２４】実施例２ 本実施例では、光とＨ2 Ｏ／Ｃｌ2 ガスを用いたシリコ
ンの熱酸化膜の形成について述べる。Example 2 In this example, formation of a thermal oxide film of silicon using light and H 2 O / Cl 2 gas will be described.
【００２５】シリコンウエハをアンモニア水過酸化水素
水／水混合液、硫酸／過酸化水素水混合液、塩酸／過酸
化水素水／水混合液を用いて洗浄し、表面のパーティク
ルや有機物、金属汚染物を除去し、さらにこれら洗浄に
よってシリコン表面に形成されたシリコン酸化膜を弗酸
を用いて除去した。このウエハを図１に示した酸化装置
の試料台１５上に載置し、ガス導入口１２からＨ2 Ｏガ
スを１０ｌ／ｍｉｎ導入しながら試料１４の温度を５０
０℃に昇温した。この処理によりウエハ表面に約１ｎｍ
の酸化膜が形成された。A silicon wafer is washed with an ammonia water / hydrogen peroxide mixture / water mixture, a sulfuric acid / hydrogen peroxide mixture, and a hydrochloric acid / hydrogen peroxide mixture / water mixture, and particles, organic substances, and metal contamination on the surface are cleaned. Then, the silicon oxide film formed on the silicon surface by these cleanings was removed by using hydrofluoric acid. The wafer was placed on the sample stage 15 of the oxidation apparatus shown in FIG. 1, 50 the temperature of the sample 14 while introducing 10l / min H 2 O gas from the gas inlet 12
The temperature was raised to 0 ° C. By this process, the wafer surface is about 1 nm
Oxide film was formed.
【００２６】次に、ガス導入口１２から導入するガスを
Ｈ2 Ｏ単体からＨ2 Ｏ／Ｃｌ2 混合ガス（Ｈ2 Ｏを１０
ｌ／ｍｉｎ、Ｃｌ2 を２ｌ／ｍｉｎ）に変えた後、試料
の温度を５００℃に保持したまま、試料にＸｅＣｌレー
ザ光（波長３８０ｎｍ）を照射し、所定の時間保持し
た。これに対し、本発明と比較するために、別の試料で
は導入するガスをＨ2 Ｏのままで、試料の温度を５００
℃から７５０℃に昇温し、所定の時間保持した。Next, the gas introduced from the gas inlet 12 is H 2 O simple substance and H 2 O / Cl 2 mixed gas (H 2 O is 10
After changing l / min and Cl 2 to 2 l / min), the sample was irradiated with XeCl laser light (wavelength 380 nm) while keeping the temperature of the sample at 500 ° C., and kept for a predetermined time. On the other hand, for comparison with the present invention, in another sample, the gas to be introduced was H 2 O, and the temperature of the sample was 500
The temperature was raised from ℃ to 750 ℃ and kept for a predetermined time.
【００２７】熱酸化膜を１０ｎｍ形成するのに必要な時
間を比較したところ、本発明は約２分であったのに対
し、比較例は約６０分であった。本発明で高速にシリコ
ンが酸化される機構は次のように説明される。Ｃｌ2 ガ
ス分子の解離エネルギーは約４５０ｎｍの光エネルギー
に等しい。したがってそれよりも波長が短く、エネルギ
ーの高い３０８ｎｍの光をＣｌ2 ガスに照射するとＣｌ
2 が解離してＣｌ原子となる。実施例１でも述べたよう
に、Ｃｌ原子はＨ2 Ｏと反応してＨＣｌとＯＨラジカル
とを生成し、ＯＨはまた相互に反応してＯラジカルを生
成する。このような活性なＯラジカルが表面付近で形成
されること及び光照射による表面励起（シリコン表面で
電子やホールが多数形成される）によりシリコンは高速
に酸化される。このように本発明を用いることにより、
５００℃という低温でかつ短時間でシリコンを酸化する
ことができた。When the time required to form a thermal oxide film of 10 nm was compared, it was about 2 minutes in the present invention, while it was about 60 minutes in the comparative example. The mechanism of rapid oxidation of silicon in the present invention is explained as follows. The dissociation energy of Cl 2 gas molecules is equal to the light energy of about 450 nm. Therefore, when Cl 2 gas is irradiated with 308 nm light having a shorter wavelength and higher energy, Cl 2 gas is irradiated.
2 dissociates into Cl atoms. As described in Example 1, Cl atom reacts with H 2 O to generate HCl and OH radical, and OH also reacts with each other to generate O radical. Silicon is rapidly oxidized due to the formation of such active O radicals near the surface and surface excitation by light irradiation (a large number of electrons and holes are formed on the silicon surface). By using the present invention in this way,
It was possible to oxidize silicon at a low temperature of 500 ° C. and in a short time.
【００２８】また、照射する光の強度分布を均一にした
ことにより、酸化膜の均一性が±０．５％以下と非常に
高かった。さらに、光の照射時間を制御することで０．
１ｎｍ単位での酸化膜厚の精密制御が可能であった。し
たがって、例えばある一定時間光を照射して酸化膜を形
成した後、装置内に保持したまま試料の膜厚を測定し、
所定の膜厚に満たなかった場合は、不足の膜厚の分だけ
光を追加照射することで、所望の膜厚の酸化膜を得るこ
ともできることがわかった。Further, by making the intensity distribution of the irradiation light uniform, the uniformity of the oxide film was as high as ± 0.5% or less. Furthermore, by controlling the irradiation time of light,
It was possible to precisely control the oxide film thickness in units of 1 nm. Therefore, for example, after irradiating light for a certain period of time to form an oxide film, the film thickness of the sample is measured while being held in the device,
It has been found that when the film thickness is less than the predetermined film thickness, an oxide film having a desired film thickness can be obtained by additionally irradiating light of an insufficient film thickness.
【００２９】なお、本発明による処理では、Ｈ2 Ｏ／Ｃ
ｌ2 ガスと光照射によって酸化膜を形成する前にＨ2 Ｏ
ガス中での５００℃昇温により薄い（約１ｎｍ）酸化膜
を形成している。これは活性なＣｌ原子がシリコンと直
接反応してシリコンをエッチングすることを抑制するた
めである。また、実施例１と同様に、本発明による処理
で形成したシリコン酸化膜に含まれる金属汚染は１×１
０9 個／ｃｍ2 以下と非常に少なかったが、これもＣｌ
原子により金属汚染物が塩化物となり除去されたためで
ある。In the treatment according to the present invention, H 2 O / C
L 2 gas and H 2 O before forming an oxide film by light irradiation
A thin (about 1 nm) oxide film is formed by raising the temperature in gas at 500 ° C. This is to suppress active Cl atoms from directly reacting with silicon to etch silicon. Further, as in Example 1, the metal contamination contained in the silicon oxide film formed by the process according to the present invention is 1 × 1.
It was very low at less than 09 pieces / cm 2 , but this too was Cl
This is because the metal contaminants became chlorides and were removed by the atoms.
【００３０】また、本発明による処理では、照射する光
の強度分布が非常に均一なため、酸化膜の均一性も±
０．５％以下と非常に高かった。さらに本処理では、光
の照射時間を制御することで０．１ｎｍ単位での酸化膜
厚の精密制御が可能である。したがって例えば、ある一
定時間光を照射して酸化膜を形成した後、図１の装置内
に保持したまま試料の膜厚を測定し、所定の膜厚に満た
なかった場合は、不足の膜厚の分だけ光を追加照射する
ことで、所望の膜厚の酸化膜を得ることができる。Further, in the treatment according to the present invention, since the intensity distribution of the irradiation light is very uniform, the uniformity of the oxide film is ±.
It was very high at 0.5% or less. Further, in this process, the oxide film thickness can be precisely controlled in units of 0.1 nm by controlling the light irradiation time. Therefore, for example, after irradiating light for a certain period of time to form an oxide film, the film thickness of the sample is measured while being held in the apparatus of FIG. By additionally irradiating light by the amount, an oxide film having a desired film thickness can be obtained.
【００３１】このように、本発明の処理を用いること
で、低温で制御性よく、かつ高速で金属汚染の少ない酸
化膜を試料面内で均一に形成することができた。なお、
本発明は上記実施例に限定されるものでなく、例えば実
施例２ではシリコン表面に薄い酸化膜を装置内部で形成
しているが、装置外部（例えば洗浄時）で形成してもよ
い。また、実施例１及び２の実施例を組み合わせて、Ｈ
2 Ｏ／Ｃｌ2 ガス中で試料を６００℃以上に保持し、か
つ４５０ｎｍ以下の光を照射すると、Ｃｌ2 が熱励起と
光励起の両方で解離するためＣｌ原子の生成量が増加
し、ＯＨ、Ｏの生成効率が上がるためより速く試料を酸
化することができる。As described above, by using the treatment of the present invention, it was possible to form an oxide film with good controllability at low temperature, at high speed, and with less metal contamination, uniformly within the sample surface. In addition,
The present invention is not limited to the above embodiment. For example, although the thin oxide film is formed on the silicon surface inside the device in the second embodiment, it may be formed outside the device (for example, during cleaning). Also, by combining the examples of Examples 1 and 2, H
When the sample is kept at 600 ° C. or higher in 2 O / Cl 2 gas and irradiated with light having a wavelength of 450 nm or less, Cl 2 is dissociated by both thermal excitation and photoexcitation, so that the amount of Cl atoms generated increases and OH, Since the production efficiency of O is increased, the sample can be oxidized more quickly.
【００３２】上記実施例では、酸素原子を含むガスとし
てＨ2 Ｏを用いたが、塩素原子を含むガスと反応し、Ｏ
Ｈラジカルを生成するものであればよい。例えば、メチ
ルアルコール等のアルコール類やフェノール類等でもよ
い。また、塩素原子を含むガスとしては、Ｃｌ2 の他に
Ｆ2 、Ｂｒ2 、Ｉ2 等のハロゲン分子のガスでもよいと
考えられる。In the above embodiment, H 2 O was used as the gas containing oxygen atoms, but it reacts with the gas containing chlorine atoms to give O 2.
Any H-radical can be used. For example, alcohols such as methyl alcohol and phenols may be used. In addition to Cl 2 , the gas containing chlorine atoms may be a gas of halogen molecules such as F 2 , Br 2 and I 2 .
【００３３】本発明により形成された熱酸化膜は、例え
ばＭＯＳトランジスタのゲート酸化膜、キャパシタ絶縁
膜、層間絶縁膜、素子分離絶縁膜等、均一な絶縁膜、熱
酸化膜を必要とする箇所であれば適用可能である。その
他、本発明の要旨を逸脱しない範囲で種々実施すること
ができる。The thermal oxide film formed according to the present invention is, for example, a gate oxide film of a MOS transistor, a capacitor insulating film, an interlayer insulating film, an element isolation insulating film, or the like where a uniform insulating film and a thermal oxide film are required. If applicable, it is applicable. Besides, various implementations can be made without departing from the scope of the present invention.
【００３４】[0034]
【発明の効果】熱酸化膜を高速かつ均一性よく形成でき
るため、半導体素子製造の歩留まりが向上し、素子の電
気特性が均一化する。Since the thermal oxide film can be formed at high speed and with good uniformity, the yield of semiconductor device production is improved and the electric characteristics of the device are made uniform.
【図１】 本発明の熱酸化膜形成方法に用いられる処理
装置の概略図。FIG. 1 is a schematic view of a processing apparatus used in a thermal oxide film forming method of the present invention.
１１・・処理容器 １２・・ガス導入口 １３・・ガス排気口 １４・・試料 １５・・試料台 １６・・ヒータ １７・・石英製の窓 11 ... Processing container 12 ... Gas inlet 13 ... Gas exhaust 14 ... Sample 15 ... Sample stand 16 ... Heater 17 ... Quartz window
Claims (7)
と、前記被処理基体の温度を所定の温度に保持すると共
に、前記容器内に酸素原子を含むガスと塩素原子を含む
ガスとを導入する工程と、前記塩素原子を含むガスを励
起する工程と、前記励起した塩素原子を含むガスで前記
酸素原子を含むガスを分解し、前記被処理基体上に熱酸
化膜を形成する工程とを具備したことを特徴とする熱酸
化膜形成方法。1. A step of accommodating a substrate to be treated in a treatment container, maintaining the temperature of the substrate to be treated at a predetermined temperature, and introducing a gas containing oxygen atoms and a gas containing chlorine atoms into the container. A step of exciting the gas containing the chlorine atom, and a step of decomposing the gas containing the oxygen atom with the gas containing the excited chlorine atom to form a thermal oxide film on the substrate to be processed. A method for forming a thermal oxide film, comprising:
は、前記被処理基体の温度を６００℃以上に昇温するこ
とを特徴とする請求項１記載の熱酸化膜形成方法。2. The method for forming a thermal oxide film according to claim 1, wherein the step of exciting the gas containing chlorine atoms raises the temperature of the substrate to be processed to 600 ° C. or higher.
は、前記容器内に前記被処理基体表面に４５０ｎｍ以下
の波長の光を照射することを特徴とする請求項１記載の
熱酸化膜形成方法。3. The thermal oxide film formation according to claim 1, wherein in the step of exciting the gas containing chlorine atoms, the surface of the substrate to be processed is irradiated with light having a wavelength of 450 nm or less in the container. Method.
を用いることを特徴とする請求項１記載の熱酸化膜形成
方法。4. The method for forming a thermal oxide film according to claim 1, wherein H 2 O gas is used as the gas containing oxygen atoms.
を用いることを特徴とする請求項１記載の熱酸化膜形成
方法。5. The method for forming a thermal oxide film according to claim 1, wherein Cl 2 gas is used as the gas containing chlorine atoms.
が形成されているものを用いることを特徴とする請求項
１記載の熱酸化膜形成方法。6. The method for forming a thermal oxide film according to claim 1, wherein a substrate on which a thin oxide film is formed is used as the substrate to be processed.
ることを特徴とする請求項１記載の熱酸化膜形成方法。7. The method for forming a thermal oxide film according to claim 1, wherein a silicon substrate is used as the substrate to be processed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23393394A JPH0897206A (en) | 1994-09-29 | 1994-09-29 | Forming method of thermal oxidation film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23393394A JPH0897206A (en) | 1994-09-29 | 1994-09-29 | Forming method of thermal oxidation film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0897206A true JPH0897206A (en) | 1996-04-12 |
Family
ID=16962893
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23393394A Pending JPH0897206A (en) | 1994-09-29 | 1994-09-29 | Forming method of thermal oxidation film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0897206A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19700867A1 (en) * | 1996-10-24 | 1998-05-07 | Lg Semicon Co Ltd | Semiconductor processing apparatus for film growing on wafer surface |
| JP2005333072A (en) * | 2004-05-21 | 2005-12-02 | Sumco Corp | Evaluation method of semiconductor substrate |
| CN115064437A (en) * | 2022-08-19 | 2022-09-16 | 广州粤芯半导体技术有限公司 | Method for manufacturing semiconductor device and semiconductor device |
-
1994
- 1994-09-29 JP JP23393394A patent/JPH0897206A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19700867A1 (en) * | 1996-10-24 | 1998-05-07 | Lg Semicon Co Ltd | Semiconductor processing apparatus for film growing on wafer surface |
| DE19700867C2 (en) * | 1996-10-24 | 1999-07-01 | Lg Semicon Co Ltd | Apparatus and method for growing a film on the surface of a wafer in semiconductor manufacturing |
| JP2005333072A (en) * | 2004-05-21 | 2005-12-02 | Sumco Corp | Evaluation method of semiconductor substrate |
| CN115064437A (en) * | 2022-08-19 | 2022-09-16 | 广州粤芯半导体技术有限公司 | Method for manufacturing semiconductor device and semiconductor device |
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