JPH038331A - Method and apparatus for forming silicon oxide - Google Patents
Method and apparatus for forming silicon oxideInfo
- Publication number
- JPH038331A JPH038331A JP14489489A JP14489489A JPH038331A JP H038331 A JPH038331 A JP H038331A JP 14489489 A JP14489489 A JP 14489489A JP 14489489 A JP14489489 A JP 14489489A JP H038331 A JPH038331 A JP H038331A
- Authority
- JP
- Japan
- Prior art keywords
- substrate
- silicon
- molecular beam
- film
- silicon oxide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 title claims abstract description 32
- 238000000034 method Methods 0.000 title claims description 22
- 229910052814 silicon oxide Inorganic materials 0.000 title claims description 15
- 239000000758 substrate Substances 0.000 claims abstract description 32
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 claims abstract description 13
- 238000006243 chemical reaction Methods 0.000 claims abstract description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 29
- 229910052760 oxygen Inorganic materials 0.000 claims description 28
- 239000001301 oxygen Substances 0.000 claims description 28
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 16
- 229910052710 silicon Inorganic materials 0.000 claims description 16
- 239000010703 silicon Substances 0.000 claims description 16
- 230000003647 oxidation Effects 0.000 claims description 13
- 238000007254 oxidation reaction Methods 0.000 claims description 13
- 230000015572 biosynthetic process Effects 0.000 claims description 8
- 230000008020 evaporation Effects 0.000 claims description 3
- 238000001704 evaporation Methods 0.000 claims description 3
- 230000001678 irradiating effect Effects 0.000 claims description 3
- 239000007789 gas Substances 0.000 claims 1
- 150000001875 compounds Chemical class 0.000 abstract description 3
- 238000000151 deposition Methods 0.000 abstract description 3
- 239000010453 quartz Substances 0.000 abstract description 3
- 239000004065 semiconductor Substances 0.000 abstract description 3
- 230000001590 oxidative effect Effects 0.000 abstract description 2
- 235000012239 silicon dioxide Nutrition 0.000 abstract 8
- 229910052681 coesite Inorganic materials 0.000 abstract 7
- 229910052906 cristobalite Inorganic materials 0.000 abstract 7
- 239000000377 silicon dioxide Substances 0.000 abstract 7
- 229910052682 stishovite Inorganic materials 0.000 abstract 7
- 229910052905 tridymite Inorganic materials 0.000 abstract 7
- 230000015556 catabolic process Effects 0.000 description 9
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 7
- 238000001947 vapour-phase growth Methods 0.000 description 6
- 235000012431 wafers Nutrition 0.000 description 5
- 239000000203 mixture Substances 0.000 description 4
- 239000013078 crystal Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000005684 electric field Effects 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 239000012808 vapor phase Substances 0.000 description 2
- 241000894006 Bacteria Species 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 229910021419 crystalline silicon Inorganic materials 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Landscapes
- Physical Vapour Deposition (AREA)
- Physical Deposition Of Substances That Are Components Of Semiconductor Devices (AREA)
Abstract
Description
【発明の詳細な説明】
(産業上の利用分野)
本発明は酸化シリコン形成方法及び形成装置に係わり、
詳しくは高品質な酸化シリコンを低温で形成する方法及
び装置に関する。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method and apparatus for forming silicon oxide,
More specifically, the present invention relates to a method and apparatus for forming high quality silicon oxide at low temperatures.
(従来の技術)
従来、シリコン酸化膜の形成方法はシリコン基板の熱酸
化もしくは、気相成長によるものであった。シリコン基
板の熱酸化によれば高品質のシリコン酸化膜が得られ、
また界面はシリコン基板内に形成されるため界面準位密
度も少ない。しかし、熱酸化のためには800°C以上
の高温を必要とし、熱酸化の過程で不純物の拡散によっ
て、基板内に形成した不純物プロファイルが崩れてしま
うという欠点がある。一方、気相成長によれば低温の酸
化膜形成が可能ではある。しかし、この気相成長では気
相中でシリコンと酸素の反応が起こり5iC)z粒子と
なって基板上に降り積もるため、酸化膜中にはボイドが
多数存在する。このため、気相成長によって形成した酸
化膜は、熱酸化膜に比べて耐圧が低くリーク電流も多い
。さらに、シリコン表面の清浄化が行われないため、界
面準位密度が多く、MOSデバイスのゲート酸化膜等高
品質の酸化膜が要求される箇所には使用することができ
ないという問題点があった。さらに、MOSデバイスの
ゲート酸化膜は、LSIの高密度化に伴い薄膜化の傾向
にあり、近い将来には100人あるいはそれ以下の膜厚
が必要になると予想される。特にDRAMでは、α線に
よるソフトエラーを防止するために容量を少なくするこ
とが困難な状況にあり、従って微細化に伴う容量の減少
を酸化膜の薄膜化で補う必要がある。さらに、チップサ
イズの大型化によりゲート領域の占める面積も広くなり
つつあり、大面積にわたって耐圧不良のない電気的絶縁
性の優れた酸化膜が要求される。一方、酸化膜が薄くな
っても動作電圧を下げること実用上困難であり、酸化膜
は従来よりも高い電界強度のもとで使用される傾向にあ
る。しかし、熱酸化膜は膜厚が薄くなると、ピンホール
やウィークスポットなど絶縁不良をひきおこす欠陥が多
数発生する。この原因はSiと5i02の界面に存在す
るSiO工層の影響が酸化膜厚が薄くなってくると無視
し得なくなってくること、また微粒子、有機物、油脂、
あるいはバクテリアの付着などによる表面の汚染である
と考えられている。(Prior Art) Conventionally, silicon oxide films have been formed by thermal oxidation of a silicon substrate or vapor phase growth. High quality silicon oxide film can be obtained by thermal oxidation of silicon substrate,
Furthermore, since the interface is formed within the silicon substrate, the density of interface states is also low. However, thermal oxidation requires a high temperature of 800° C. or higher, and there is a drawback that the impurity profile formed in the substrate is destroyed by diffusion of impurities during the thermal oxidation process. On the other hand, vapor phase growth allows formation of an oxide film at low temperatures. However, in this vapor phase growth, a reaction between silicon and oxygen occurs in the vapor phase, forming 5iC)z particles that accumulate on the substrate, so that many voids are present in the oxide film. Therefore, an oxide film formed by vapor phase growth has a lower breakdown voltage and more leakage current than a thermal oxide film. Furthermore, since the silicon surface is not cleaned, there is a large density of interface states, making it unsuitable for use in areas where high-quality oxide films are required, such as gate oxide films in MOS devices. . Furthermore, gate oxide films of MOS devices tend to become thinner as LSIs become more densely packed, and it is expected that a film thickness of 100 mm or less will be required in the near future. Particularly in DRAMs, it is difficult to reduce the capacity to prevent soft errors caused by alpha rays, and therefore it is necessary to compensate for the decrease in capacity due to miniaturization by making the oxide film thinner. Furthermore, as the chip size increases, the area occupied by the gate region becomes larger, and an oxide film with excellent electrical insulation properties without breakdown voltage defects is required over a large area. On the other hand, even if the oxide film becomes thinner, it is practically difficult to lower the operating voltage, and oxide films tend to be used under higher electric field strength than before. However, as the thermal oxide film becomes thinner, many defects such as pinholes and weak spots occur that cause insulation failure. The reason for this is that the influence of the SiO layer existing at the interface between Si and 5i02 becomes negligible as the oxide film becomes thinner, and also that the influence of the SiO layer existing at the interface between Si and 5i02 becomes negligible as the oxide film becomes thinner.
Alternatively, it is thought that the surface may be contaminated due to adhesion of bacteria.
そこで、発明者は検討を重ね分子状のSiと02を同時
に基板に供給したところ、低温で酸化膜が形成できるこ
とを見出した。また、この方法では気相成長により酸化
膜の堆積と異なり分子線領域で行うため、気相反応では
なく表面でのSiの酸化が生じる。このため、気相成長
に比べてよりちみっな膜の形成が行えることがわかった
。さらに、5i02形成前にSi分子線成長法でSiの
バッファーエピタキシャル層を成長することによって5
i02/Si界面を原子オーダーで平坦にすることがで
き、界面の凹凸による電界集中に起因する耐圧の低下及
び界面遷移層に起因する界面準位密度を減少させること
ができた。しかし、非常に希薄な酸素雰囲気中での成長
では、膜内に取り込まれる酸素濃度は成長温度に大きく
依存し、成長温度が低いほど高くなりた。さらに、室温
で成長しても酸素量が足りないために膜中の酸素濃度は
SiOのストイキオメトリ−より低いものになる。この
様な酸化膜の耐圧は低く、リーク電流も多かった。Therefore, the inventor conducted extensive research and found that an oxide film could be formed at a low temperature by simultaneously supplying molecular Si and O2 to the substrate. Furthermore, unlike the deposition of an oxide film by vapor phase growth, this method is performed in a molecular beam region, so oxidation of Si occurs on the surface rather than a vapor phase reaction. For this reason, it was found that a thinner film could be formed compared to vapor phase growth. Furthermore, by growing a Si buffer epitaxial layer using the Si molecular beam growth method before forming 5i02,
It was possible to make the i02/Si interface flat on the atomic order, and it was possible to reduce the breakdown voltage caused by electric field concentration due to the unevenness of the interface and the interface state density caused by the interface transition layer. However, when growing in a very dilute oxygen atmosphere, the oxygen concentration incorporated into the film was highly dependent on the growth temperature, and the lower the growth temperature, the higher it was. Furthermore, even if the film is grown at room temperature, the oxygen concentration in the film is lower than the stoichiometry of SiO because the amount of oxygen is insufficient. Such an oxide film had a low breakdown voltage and a large leakage current.
本発明の目的は、この様な従来の欠点を除去せしめて、
高品質な酸化シリコンを低温で形成する方法及び装置を
提供することにある。The purpose of the present invention is to eliminate such conventional drawbacks,
An object of the present invention is to provide a method and apparatus for forming high quality silicon oxide at low temperatures.
(課題を解決するための手段)
本発明は、基板上にシリコン(Si)分子線とオゾン(
O3)分子線もしくはオゾンを含む酸素(O□)分子線
を同時に照射することを特徴とする酸化シリコン形成方
法と真空槽内にシリコン分子発生用として電子銃蒸着装
置と、オゾン分子線発生用として紫外光照射可能な反応
管とこれにつながり真空槽内にオゾンを噴出するための
ノズルをそなえてなることを特徴とする酸化シリコン形
成装置である。また、酸化シリコンを上記方法により形
成する前に基板上に分子線成長方法によりシリコンエピ
タキシャル層を成長すると酸化シリコンとシリコンの界
面を良好なものとすることができる。(Means for Solving the Problems) The present invention provides silicon (Si) molecular beams and ozone (
O3) A silicon oxide formation method characterized by simultaneous irradiation with a molecular beam or an oxygen (O□) molecular beam containing ozone, an electron gun evaporation device in a vacuum chamber for generating silicon molecules, and an ozone molecular beam generation This silicon oxide forming apparatus is characterized by comprising a reaction tube capable of irradiating ultraviolet light and a nozzle connected to the reaction tube for spouting ozone into a vacuum chamber. Furthermore, if a silicon epitaxial layer is grown on the substrate by a molecular beam growth method before silicon oxide is formed by the above method, the interface between silicon oxide and silicon can be made good.
(作用)
本発明の原理について説明する。02分子は室温近傍の
低温でも容易に清浄表面上に解離吸着する。しかし、従
来の基板熱酸化では、酸化は5iOzと基板Si結晶界
面において起こっているため、酸素の5i02中での拡
散と基板結晶Siのバックボンドを切るために多くのエ
ネルギーを必要とし、これが酸化温度と時間を決定して
いる。第2図に示すように、表面側から分子状のSiと
02を同時に供給すると、酸化はいつも表面で起こり、
しかも結晶を組んでいる基板Siのバックボンドを切る
必要がないため、低温で酸化膜が形成できる。しかし、
以上のような酸化膜形成方法ではSi分子発生源として
電子銃式蒸着装置を用いるため、Si分子と同時に照射
する酸素の分圧を1 x 10−’Torr以上に上げ
ることは難しく、この様に、非常に希薄な酸素雰囲気中
での成長では、膜内に取りこまれる酸素濃度は成長温度
に大きく依存し、成長温度が低いほど高くなた。さらに
、温室で成長しても酸素量が足りないために膜中の酸素
濃度は5102のストイキオメトリ−より低いものにな
る。この様な酸化膜の耐圧は低く、ソーク電流も多かっ
た。そこで、発明者は、酸素の酸化力を増大させるため
に、第1図に示すように、紫外光照射した合成石英製反
応管中に酸素を流すことによって、酸素をオゾンもしく
はオゾンと酸素分子線の混合したものとして供給したと
ころ、形成された酸化膜中の酸素濃度が、02分子線を
照射した場合に比べて、飛躍的に増加することを見出し
た。この様にして成長した膜では成長温度が300°C
でも膜中の酸素濃度は5i02のストイキオメトリ−に
一致し、耐圧、リーク電流、界面準位密度共に熱酸化に
よって形成された酸化膜と同程度のものを作ることがで
きた。(Operation) The principle of the present invention will be explained. 02 molecules easily dissociate and adsorb onto clean surfaces even at low temperatures near room temperature. However, in conventional substrate thermal oxidation, oxidation occurs at the interface between 5iOz and substrate Si crystals, so a lot of energy is required to diffuse oxygen in 5iO2 and break the back bond of substrate crystalline Si, which causes oxidation. It determines the temperature and time. As shown in Figure 2, when molecular Si and O2 are simultaneously supplied from the surface side, oxidation always occurs at the surface.
Moreover, since there is no need to cut the back bond of the Si substrate on which the crystal is assembled, the oxide film can be formed at low temperatures. but,
In the above oxide film formation method, an electron gun type evaporation device is used as the Si molecule generation source, so it is difficult to increase the partial pressure of oxygen that is irradiated simultaneously with Si molecules to more than 1 x 10-'Torr. When growing in a very dilute oxygen atmosphere, the oxygen concentration incorporated into the film was highly dependent on the growth temperature, and the lower the growth temperature, the higher it was. Furthermore, even when grown in a greenhouse, the oxygen concentration in the film is lower than the stoichiometry of 5102 because the amount of oxygen is insufficient. Such an oxide film had a low breakdown voltage and a large soak current. Therefore, in order to increase the oxidizing power of oxygen, the inventors introduced oxygen into ozone or ozone and oxygen molecular beams by flowing oxygen into a synthetic quartz reaction tube irradiated with ultraviolet light, as shown in Figure 1. It has been found that when the oxide film is supplied as a mixture of the following, the oxygen concentration in the formed oxide film increases dramatically compared to the case where the 02 molecular beam is irradiated. The film grown in this way has a growth temperature of 300°C.
However, the oxygen concentration in the film matched the stoichiometry of 5i02, and the breakdown voltage, leakage current, and interface state density were comparable to those of the oxide film formed by thermal oxidation.
本方法は、基板Siを酸化するものではなく、Siも表
面から供給するために、基板はSiである必要はなく、
他の材料例えば化合物半導体上でも同様な酸化膜が得ら
れた。This method does not oxidize the substrate Si, and since Si is also supplied from the surface, the substrate does not need to be Si.
Similar oxide films were also obtained on other materials, such as compound semiconductors.
(実施例)
発明の実施例について具体的に説明する。実験は40c
cの電子銃式Si蒸着器を備えた分子線成長(MBE)
装置を用いて行った。試料ウェハーには4インチn型5
i(100)、(111)0.01〜0.02Ωcm基
板を用いた。(Example) Examples of the invention will be specifically described. The experiment is 40c
Molecular beam growth (MBE) equipped with an electron gun type Si evaporator
This was done using a device. The sample wafer has a 4-inch n-type 5
i(100), (111) 0.01 to 0.02 Ωcm substrates were used.
試料ウェハーはRCA洗浄後、形成室内に搬送し10人
のa−8iを堆積後、800°011分間の洗浄化を行
い、洗浄面を出し、成長温度500°Cでバッファ層で
あるエピタキシャル層を3000人成長した。基板温度
を形成温度に下げた後、ノズルから30〜40%のオゾ
ンを含んだ酸素を形成室内にリークし電子銃式Si蒸着
器から、5in2の形成速度換算で0.55A/SのS
i分子線を照射し清浄面上に酸化膜を形成した。酸素分
圧は5X10 Torr一定とし形成温度を室温から7
50°Cまで変化させた。形成膜厚は約1000人あっ
た。オゾンは純度99.9999%の酸素を合成石英反
応管に導入し、これに出力IKWのHg−Xeランプを
照射し形成した。酸素の流量は31/minでこのとき
のオゾン濃度は30〜40%であった。After RCA cleaning, the sample wafer was transported into the formation chamber, and after depositing 10 A-8I layers, it was cleaned for 800°011 minutes, the cleaned surface was exposed, and an epitaxial layer as a buffer layer was formed at a growth temperature of 500°C. We have grown by 3,000 people. After lowering the substrate temperature to the forming temperature, oxygen containing 30 to 40% ozone is leaked into the forming chamber from the nozzle, and an S of 0.55 A/S (converted to a forming rate of 5 in 2) is released from the electron gun type Si evaporator.
An oxide film was formed on the clean surface by irradiation with i-molecule beam. The oxygen partial pressure was kept constant at 5×10 Torr, and the formation temperature was changed from room temperature to 7.
The temperature was varied up to 50°C. The thickness of the film formed was approximately 1,000 people. Ozone was formed by introducing oxygen with a purity of 99.9999% into a synthetic quartz reaction tube and irradiating it with a Hg-Xe lamp with an output of IKW. The oxygen flow rate was 31/min, and the ozone concentration at this time was 30 to 40%.
はじめに、形成された膜の組成を調べるためにxPS観
察を行った。膜圧は100人一定とした。第2図に5i
2pコアレベルビークの変化を示す。図かられがる様に
、形成)1度が下がるにしたがって、5i2pビークは
高エネルギー側ヘシフトし室温ではSiOに対応するピ
ーク位置となった。これより、形成温度が低いほど膜の
組成は5i02に近づくことがわがる。また、室温及び
200°C形成の5i2pスペクトルにおいて8102
ピークの低エネルギー側には、酸素照射のみによって得
られた膜に見られた肩がなく、これらの膜が完全にSi
O2のストイキオメトリ−に合っていることがわかった
。次に本方法で形成した酸化膜の電気的特性について調
べた。第3図は■特性の基板温度依存性を示したもので
ある。基板温度が室温及び200°Cではリーク電流も
少なく 70Vの時でもブレークダウンがおきていない
が、基板温度が400°C以上になると、すぐにブレー
クダウンンがおこってしまい、また、リーク電流も多い
ことがわかった。400℃になると電気特性が悪化する
のは、第2図に示したxPSのデータかられかるように
、この温度では組成がSiO□からずれるためであると
考えられる。また、室温で成長したものと200°Cで
成長したものを比べると、200°Cで成長したものの
方がリーク電流がすくない。これは、ストイキオメトリ
−が合っている領域では成長温度が高い方がよりちみつ
な膜が形成できるからであると考えられる。First, xPS observation was performed to investigate the composition of the formed film. The membrane pressure was kept constant for 100 people. 5i in Figure 2
2p shows changes in core level peak. As can be seen from the figure, as the temperature (formation) decreases by 1 degree, the 5i2p peak shifts to the higher energy side and becomes the peak position corresponding to SiO at room temperature. It can be seen from this that the lower the formation temperature, the closer the film composition becomes to 5i02. In addition, in the 5i2p spectrum formed at room temperature and at 200 °C, 8102
On the low energy side of the peak, there is no shoulder seen in films obtained only by oxygen irradiation, indicating that these films are completely made of Si.
It was found that the O2 stoichiometry was met. Next, we investigated the electrical properties of the oxide film formed by this method. FIG. 3 shows the substrate temperature dependence of the characteristics. When the board temperature is room temperature or 200°C, the leakage current is small and no breakdown occurs even at 70V, but when the board temperature exceeds 400°C, breakdown occurs immediately and the leakage current also increases. I found out that there are many. The reason why the electrical characteristics deteriorate at 400° C. is considered to be because the composition deviates from SiO□ at this temperature, as seen from the xPS data shown in FIG. Furthermore, when comparing those grown at room temperature and those grown at 200°C, the one grown at 200°C has less leakage current. This is considered to be because a higher growth temperature allows a more honeyed film to be formed in a region where the stoichiometry is appropriate.
次に、02雰囲気で形成した膜と、o3雰囲気で形成し
た膜を比較するために、それぞれの方法で形成した膜の
■特性の膜厚依存性を調べた。膜厚は200人、500
人、1000人とした。第4図に結果を示す。a)は5
×lO°5Torrの02雰囲気で形成した膜、b)は
5 X 10’Torrの03を含む02雰囲気で形成
した膜である。これより、03を含む02雰囲気で形成
した膜の方が、02雰囲気で形成した膜より3桁以上リ
ーク電流が低く、ブレークダウン電流も大きいことがわ
かな。Next, in order to compare the films formed in the O2 atmosphere and the films formed in the O3 atmosphere, the film thickness dependence of the characteristics of the films formed by each method was investigated. Film thickness is 200 and 500
The number of people was 1,000. Figure 4 shows the results. a) is 5
A film formed in an 02 atmosphere of ×lO°5 Torr, b) is a film formed in an 02 atmosphere containing 03 of 5×10′ Torr. From this, it can be seen that the leakage current of the film formed in the 02 atmosphere containing 03 is lower than that of the film formed in the 02 atmosphere by more than three orders of magnitude, and the breakdown current is also larger.
最後に、本方法で形成した5i02/Si界面の平坦性
を評価するために5i(100)面上に500°Cで3
000人のエピタキシャルバッファー層を成長後、成長
温度200°Cで5 X 10’Torrの0を含む0
の雰囲気中で2
50人のSiO□を形成し界面の断面格子像を観察した
。Finally, in order to evaluate the flatness of the 5i02/Si interface formed by this method, three
After growing an epitaxial buffer layer of 0.000%, the growth temperature is 200°C and 5 x 10'Torr.
250 SiO□ were formed in an atmosphere of
MBEでバッファー層を成長しているため界面は極めて
平坦であり、界面の乱れは通常の5i(100)ウェハ
ーを用いた場合、数100人ごとに観察される1原子層
ステップだけであった。これはもとのMBE成長バッフ
ァー層上に存在するものである。この1原子層ステップ
の密度はウェハー表面の傾きに依存し、正確にjust
面を使った場合、数1000人の平坦なテラスを得るこ
とができた。この様に、MBEでエピタキシャルバッフ
ァー層を成長後、SiOを形成したMOSキャパシター
の界面準位密度をcv法により推定したところ、10
am’台であり熱酸化によって得られる界面と同等であ
った。Because the buffer layer was grown by MBE, the interface was extremely flat, and when a normal 5i (100) wafer was used, the only disturbance at the interface was a one-atomic layer step that would be observed every few hundred. This is what is present on the original MBE growth buffer layer. The density of this one-atomic layer step depends on the slope of the wafer surface and is exactly
When using surfaces, it was possible to obtain a flat terrace for several thousand people. In this way, after growing an epitaxial buffer layer by MBE, the interface state density of a MOS capacitor formed with SiO was estimated by the CV method, and it was found to be 10
am' level, and was equivalent to the interface obtained by thermal oxidation.
なお、本実施例ではシリコンウェハーを対象トしたが、
本発明の方法は表面にのみシリコンが依存する5O8(
Silicon on 5apphire)基板や更に
一般に5OI(Silicon on In5ulat
or)基板等にも当然適用できる。また、本方法は、基
板Siを酸化するのではなく、Siも表面から供給する
ために、本質的に基板はSiである必要はなく、化合物
半導体上でも同様に良質な酸化膜が得られることを確認
した。Note that in this example, silicon wafers were targeted;
The method of the present invention uses 5O8(
Silicon on 5apphire) substrates and more generally 5OI (Silicon on In5ulat) substrates.
or) Of course, it can also be applied to substrates, etc. In addition, since this method does not oxidize the substrate Si but also supplies Si from the surface, the substrate does not essentially need to be Si, and a high-quality oxide film can be obtained on a compound semiconductor as well. It was confirmed.
(発明の効果)
以上、詳細に述べた通り本発明によれば、酸化は常に表
面上で行われるため、基板Siバックボンドを切ったり
酸化膜中で酸素を拡散させる必要もないので200°C
から300°Cの低い成長温度でも電気的に熱酸化膜と
同等な酸化膜の形成を行うことができる。また、Siの
エピタキシャルバッファー層上に酸化膜を形成すること
によって、原子オーダーで平坦な酸化膜とシリコンの界
面を得ることができる。酸素(O2)に紫外照射した後
、酸素原料分子線としてSi分子線と共にSi供給すれ
ばスイトキオメトリーのとれた酸化膜が得られる。(Effects of the Invention) As described above in detail, according to the present invention, oxidation is always performed on the surface, so there is no need to cut the substrate Si back bond or diffuse oxygen in the oxide film, so
An oxide film electrically equivalent to a thermal oxide film can be formed even at a low growth temperature of from 300°C. Furthermore, by forming an oxide film on the Si epitaxial buffer layer, it is possible to obtain an atomically flat interface between the oxide film and silicon. If oxygen (O2) is irradiated with ultraviolet rays and then Si is supplied together with a Si molecular beam as an oxygen source molecular beam, an oxide film with good sweetochiometry can be obtained.
第1図は、本発明の装置の概念図、
第2図は、成長温度を変化させた時のxPSの5i2p
コアベルスペクトルの変化を示す図、
第3図は、■特性の基板温度依存性を示す図、第4図は
、(a)、(b)は酸化シリコン膜の■特性の膜厚依存
性を示す図で各々0□雰囲気で形成した膜と、o3雰囲
気で形成した膜について■特性の膜厚依存性を示す図で
ある。Figure 1 is a conceptual diagram of the apparatus of the present invention. Figure 2 shows the 5i2p of xPS when the growth temperature is changed.
Figure 3 shows the dependence of ■characteristics on substrate temperature; Figure 4 shows (a) and (b) the dependence of ■characteristics on film thickness of silicon oxide film. FIG. 3 is a diagram showing the film thickness dependence of the ■characteristics for a film formed in a 0□ atmosphere and a film formed in an O3 atmosphere.
Claims (1)
)分子線もしくはオゾンを含む酸素(O_2)分子線を
同時に照射することを特徴とする酸化シリコン形成方法
。 2、基板上にSi分子線成長方法によりSiエピタキシ
ャル層を成長させる工程と、このSiエピタキシャル層
上に請求項1記載の方法により酸化シリコンを形成させ
る工程とを備えてなることを特徴とする酸化シリコン形
成方法。 3、基板設置可能な真空槽内にシリコン分子線発生用電
子銃式蒸着装置と、オゾン分子線発生用ノズルとを備え
、前記ノズルは酸素導入口を有する反応管につながり前
記反応管は反応管内に導入されたガスに照射可能な紫外
光照射手段を備えてなることを特徴とする酸化シリコン
形成装置。[Claims] 1. Silicon (Si) molecular beams and ozone (O_3
) A silicon oxide forming method characterized by simultaneous irradiation with a molecular beam or an oxygen (O_2) molecular beam containing ozone. 2. Oxidation characterized by comprising the steps of growing a Si epitaxial layer on a substrate by a Si molecular beam growth method, and forming silicon oxide on this Si epitaxial layer by the method according to claim 1. Silicon formation method. 3. A vacuum chamber in which a substrate can be installed is equipped with an electron gun evaporation device for generating silicon molecular beams and a nozzle for generating ozone molecular beams, and the nozzle is connected to a reaction tube having an oxygen inlet, and the reaction tube is connected to the inside of the reaction tube. 1. A silicon oxide forming apparatus comprising: ultraviolet light irradiation means capable of irradiating gas introduced into the silicon oxide forming apparatus.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP14489489A JPH038331A (en) | 1989-06-06 | 1989-06-06 | Method and apparatus for forming silicon oxide |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP14489489A JPH038331A (en) | 1989-06-06 | 1989-06-06 | Method and apparatus for forming silicon oxide |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH038331A true JPH038331A (en) | 1991-01-16 |
Family
ID=15372814
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP14489489A Pending JPH038331A (en) | 1989-06-06 | 1989-06-06 | Method and apparatus for forming silicon oxide |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH038331A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100713264B1 (en) * | 1999-07-09 | 2007-05-04 | 어플라이드 머티어리얼스, 인코포레이티드 | Method and a system for sealing an epitaxial silicon layer on a substrate |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5984420A (en) * | 1982-09-30 | 1984-05-16 | ウエスタ−ン・エレクトリツク・カムパニ−・インコ−ポレ−テツド | Method of producing product including multicomponent material covering substrate |
JPS62237733A (en) * | 1986-04-08 | 1987-10-17 | Nec Corp | Oxidation and apparatus therefor |
JPS6473714A (en) * | 1987-09-16 | 1989-03-20 | Sanyo Electric Co | Formation of semiconductor thin film |
-
1989
- 1989-06-06 JP JP14489489A patent/JPH038331A/en active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5984420A (en) * | 1982-09-30 | 1984-05-16 | ウエスタ−ン・エレクトリツク・カムパニ−・インコ−ポレ−テツド | Method of producing product including multicomponent material covering substrate |
JPS62237733A (en) * | 1986-04-08 | 1987-10-17 | Nec Corp | Oxidation and apparatus therefor |
JPS6473714A (en) * | 1987-09-16 | 1989-03-20 | Sanyo Electric Co | Formation of semiconductor thin film |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100713264B1 (en) * | 1999-07-09 | 2007-05-04 | 어플라이드 머티어리얼스, 인코포레이티드 | Method and a system for sealing an epitaxial silicon layer on a substrate |
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