JP2669655B2 - Ultrasonic cleaning equipment - Google Patents
Ultrasonic cleaning equipmentInfo
- Publication number
- JP2669655B2 JP2669655B2 JP63182493A JP18249388A JP2669655B2 JP 2669655 B2 JP2669655 B2 JP 2669655B2 JP 63182493 A JP63182493 A JP 63182493A JP 18249388 A JP18249388 A JP 18249388A JP 2669655 B2 JP2669655 B2 JP 2669655B2
- Authority
- JP
- Japan
- Prior art keywords
- cleaning
- ultrasonic
- cleaning liquid
- semiconductor substrate
- cleaning tank
- 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.)
- Expired - Fee Related
Links
Landscapes
- Cleaning By Liquid Or Steam (AREA)
- Cleaning Or Drying Semiconductors (AREA)
Description
【発明の詳細な説明】 ［発明の目的］ （産業上の利用分野） 本発明は、半導体基板（ウエーハとも呼ぶ）の表面に
付着した汚染物を、洗浄液に浸漬して除去する超音波洗
浄装置に関するもので、特に半導体製造プロセスにおい
て、基板に付着する極微小の粒子状又は被膜状の汚染物
の除去に使用される。DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to an ultrasonic cleaning apparatus for removing contaminants adhering to the surface of a semiconductor substrate (also referred to as a wafer) by immersing them in a cleaning liquid. In particular, it is used for removing extremely fine particulate or film-like contaminants adhering to a substrate in a semiconductor manufacturing process.
（従来の技術） 従来の最も一般的な半導体基板用の超音波洗浄装置
は、第８図に示すように、洗浄槽１の底部に振動板２を
含む超音波振動子３を配置し、該振動子より超音波を発
振させ、槽内に満たされた洗浄液４に超音波振動を与え
ると共に半導体基板５を該液に浸漬し、基板表面を洗浄
するものである。なお、洗浄液４は洗浄槽１の側壁に設
けられた洗浄液供給口６より流入し洗浄槽上部より放流
される。(Prior Art) As shown in FIG. 8, the most common conventional ultrasonic cleaning apparatus for semiconductor substrates has an ultrasonic vibrator 3 including a vibration plate 2 arranged at the bottom of a cleaning tank 1, Ultrasonic waves are oscillated by the vibrator to apply ultrasonic vibration to the cleaning liquid 4 filled in the bath, and the semiconductor substrate 5 is immersed in the liquid to clean the substrate surface. The cleaning liquid 4 flows in from a cleaning liquid supply port 6 provided on the side wall of the cleaning tank 1 and is discharged from the upper part of the cleaning tank.
この装置では、振動板２を介して超音波振動子３から
洗浄液内に入射された超音波は、洗浄液面に達すると、
空気との界面でその一部が反射される。このように伝播
方向が互いに反対の入射波と反対波とが重畳されると周
知のように定在波７が発生し、その振幅に対応して、洗
浄液内に音圧の強弱分布が生ずる。In this device, when the ultrasonic waves that have entered the cleaning liquid from the ultrasonic transducer 3 via the vibration plate 2 reach the cleaning liquid surface,
Part of it is reflected at the interface with air. When the incident wave and the opposite wave whose propagation directions are opposite to each other are thus superimposed, a standing wave 7 is generated as is well known, and a strong and weak distribution of sound pressure is generated in the cleaning liquid in accordance with the amplitude.
超音波洗浄装置は、その発振周波数により主に２通り
に分けられる。第１は20ないし40kHzの発振周波数帯域
に属するもので、その汚染物除去作用は主としてキャビ
テーションによるものである。一般に強い超音波が液体
内を伝播する場合、その音圧が負（稀薄化位相）になる
と、液体内に気泡（空洞）が発生する。この現象をキャ
ビテーション（空洞現象）という。引続き音圧が変化し
て正（圧縮化位相）になると気泡は急速に圧縮されて潰
される。このとき局所的な高圧と高温を伴う衝撃波が発
生し、固体表面に破壊的な作用を及ぼし汚染物等が遊離
除去される。The ultrasonic cleaning device is mainly classified into two types according to its oscillation frequency. The first one belongs to the oscillation frequency band of 20 to 40 kHz, and its pollutant removal action is mainly due to cavitation. Generally, when a strong ultrasonic wave propagates in a liquid, when the sound pressure becomes negative (diluted phase), bubbles (cavities) are generated in the liquid. This phenomenon is called cavitation (cavitation phenomenon). When the sound pressure subsequently changes and becomes positive (compression phase), the bubbles are rapidly compressed and crushed. At this time, a shock wave accompanied by local high pressure and high temperature is generated, which exerts a destructive action on the solid surface and contaminants and the like are separated and removed.
液内に定在液が形成されている場合には、キャビテー
ション振幅最大の腹の部分に発生しやすいところから、
20ないし40kHzの発振周波数帯に属する超音波洗浄装置
では定在波が起りやすいように洗浄槽が設計されてい
る。定在波の腹の部分は、例えば40kHzでは、水中にお
いて約19mmおきであり、洗浄効果の高いところが局在し
てしまう。このため半導体基板表面の除去対象となる汚
染物の大きさが微小となるに従って洗浄効果が低下する
という問題点がある。When a standing liquid is formed in the liquid, it tends to occur in the antinode of the cavitation amplitude maximum,
In the ultrasonic cleaning device belonging to the oscillation frequency band of 20 to 40 kHz, the cleaning tank is designed so that standing waves are likely to occur. The antinode portion of the standing wave is approximately every 19 mm in water at 40 kHz, for example, and the portion having a high cleaning effect is localized. For this reason, there is a problem that the cleaning effect decreases as the size of contaminants to be removed from the semiconductor substrate surface becomes smaller.
第９図及び第10図は、この問題点を改善するために提
案された従来例の超音波洗浄装置の模式図である。なお
第８図と同じ符号は同一部分又は対応部分を表わす。上
記２つの装置は、いずれも洗浄液内の定在波の発生を防
止して上記問題点を解決しようとしたものである。両装
置とも洗浄槽１の側壁に振動板12を含む超音波振動子13
を設ける。第９図に示す超音波洗浄装置では、振動板12
に対向する側壁に、傾斜する反射板８を設け、振動板12
から洗浄液内に入射される超音波をこの反射板８により
液面の方向に反射させ、定在波の発生を防止し、超音波
の洗浄効果を平均化しようとしたものである。第10図に
示す超音波洗浄装置（特開昭60−193577号）は振動板12
に対向する側壁に超音波吸収体９を設け定在波の発生を
防止したものである。いずれの場合でも定在波の発生は
防止され、超音波による洗浄効果は平均化されるが、そ
れと同時にキャビテーションの発生頻度が少なく、洗浄
効果が弱くなる。特に除去対象の汚染物の大きさが微小
になると、洗浄効果は極めて不十分となる。FIG. 9 and FIG. 10 are schematic views of a conventional ultrasonic cleaning apparatus proposed to improve this problem. The same reference numerals as in FIG. 8 represent the same or corresponding parts. Both of the above two devices are intended to solve the above problems by preventing the generation of standing waves in the cleaning liquid. Both devices have an ultrasonic vibrator 13 including a vibration plate 12 on the side wall of the cleaning tank 1.
Is provided. In the ultrasonic cleaning apparatus shown in FIG.
The inclined reflecting plate 8 is provided on the side wall facing the
The ultrasonic wave incident on the cleaning liquid is reflected by the reflector 8 in the direction of the liquid surface to prevent the generation of standing waves and to average the cleaning effect of the ultrasonic wave. The ultrasonic cleaning device (Japanese Patent Laid-Open No. Sho 60-193577) shown in FIG.
An ultrasonic absorber 9 is provided on the side wall opposite to the above to prevent the generation of standing waves. In either case, the generation of standing waves is prevented and the cleaning effect by ultrasonic waves is averaged, but at the same time, the frequency of cavitation is low and the cleaning effect is weakened. In particular, when the size of the contaminant to be removed is very small, the cleaning effect becomes extremely insufficient.
次に超音波洗浄装置の発振周波数による分類の第２の
ものは、1MHz近傍の発振周波数帯域に属する装置であ
る。この第２の場合には、前記第１の低周波数帯域の場
合に比べキャビテーションの発成期間が短く、キャビテ
ーションの発生は弱くなるが、その代わり液体分子の振
動加速度が高くなり、その結果液体分子の運動による表
面付着物の洗浄作用が強くなると考えられている。従っ
て0.1ないし1.0μｍ程度の微小な粒子や汚れを除去する
ことが可能である。便宜上この洗浄作用を粒子加速機構
による洗浄作用と呼ぶ。Next, the second category of the ultrasonic cleaning apparatus according to the oscillation frequency is an apparatus belonging to an oscillation frequency band near 1 MHz. In the second case, the cavitation generation period is shorter and the cavitation generation is weaker than in the case of the first low frequency band, but instead, the vibration acceleration of the liquid molecule is high, and as a result, the liquid molecule is increased. It is considered that the cleaning action of the surface adhered substances is enhanced by the movement of. Therefore, it is possible to remove fine particles and stains of about 0.1 to 1.0 μm. For convenience, this cleaning action is called a cleaning action by the particle acceleration mechanism.
第８図に示す従来の超音波洗浄装置と同じ構成で、そ
の超音波振動子の発振周波数を1MHzとした場合には、定
在波の腹の間隔は約0.7mmと狭くなるが、1.0μｍ程度の
デザインルールの半導体デバイスにとっては除去対象の
汚染物の大きさも微小化し、洗浄作用の弱い領域ができ
ることとなり、その歩留りに大きな影響を及ぼす。又第
９図及び第10図に示す従来の超音波洗浄装置で超音波振
動子の発振周波数を1MHzとした場合には、前述のように
定在波の発生はなく、むらのない粒子加速機構による洗
浄効果が得られるが、反射板８又は吸収体９は、振動板
12から入射される超音波の強い直接照射を受け、汚損劣
化し、洗浄液内へその遊離物が粒状となって浮遊し、洗
浄効果の低下をもたらすという欠点がある。With the same configuration as the conventional ultrasonic cleaning apparatus shown in FIG. 8, when the oscillation frequency of the ultrasonic transducer is set to 1 MHz, the interval between the antinodes of the standing wave becomes as small as about 0.7 mm, but 1.0 μm For semiconductor devices having a design rule of a certain degree, the size of contaminants to be removed is also miniaturized, and regions where the cleaning action is weak are created, which greatly affects the yield. Further, in the conventional ultrasonic cleaning apparatus shown in FIGS. 9 and 10, when the oscillation frequency of the ultrasonic vibrator is set to 1 MHz, the standing wave does not occur as described above, and the uniform particle acceleration mechanism. Although the cleaning effect can be obtained by the above, the reflecting plate 8 or the absorber 9 is a vibrating plate.
There is a drawback in that it receives strong direct irradiation of ultrasonic waves coming from 12 and contaminates and degrades, and its free substances are suspended in the cleaning liquid in the form of granules, which lowers the cleaning effect.
（発明が解決しようとする課題） 半導体デバイスの高集積密度化、微細化の進展に伴
い、半導体基板上に付着する除去対象となる微粒子状の
汚染物の大きさは0.1ないし1.0μｍ程度の極微小となっ
ている。(Problems to be Solved by the Invention) With the progress of high integration density and miniaturization of semiconductor devices, the size of the particulate contaminants to be removed attached to the semiconductor substrate is about 0.1 to 1.0 μm. It is small.
前述のように、超音波洗浄作用が主としてキャビテー
ション機構に基づく20ないし40kHzの従来の洗浄装置で
は、これらの極微小汚染物に対してはその洗浄効果が少
ない。As described above, a conventional cleaning apparatus of 20 to 40 kHz whose ultrasonic cleaning action is mainly based on a cavitation mechanism has a small cleaning effect on these extremely small contaminants.
又超音波洗浄作用が主として粒子加速機構に基づく1M
Hz程度の従来の洗浄装置でも極微小汚染物の除去に対し
ては欠点がある。例えば第８図に示す従来装置では、波
長は短いが定在波が形成され、半導体基板面に対する超
音波洗浄効果が不均一になるという欠点は解決されな
い。第９図ないし第10図の従来装置では、定在波の発生
は防止され、洗浄効果の不均一性は改善されるが、反射
板や吸収体等が超音波の照射により新しい汚染源にな
り、洗浄効果を低下させる。このため最近は、異なる発
振周波数帯域に属する複数の超音波振動子を設けて不均
一性と改善することが考えられている。Also, the ultrasonic cleaning action is mainly 1M based on the particle acceleration mechanism.
Even conventional cleaning equipment at about Hz has drawbacks for removing micro-polluted contaminants. For example, the conventional apparatus shown in FIG. 8 does not solve the drawback that a standing wave is formed although the wavelength is short, and the ultrasonic cleaning effect on the surface of the semiconductor substrate becomes non-uniform. In the conventional device shown in FIGS. 9 to 10, the generation of standing waves is prevented and the nonuniformity of the cleaning effect is improved, but the reflector and the absorber become a new pollution source due to the irradiation of ultrasonic waves. Decrease the cleaning effect. For this reason, it has recently been considered to improve the non-uniformity by providing a plurality of ultrasonic transducers belonging to different oscillation frequency bands.
本発明の目的は、半導体基板に付着する極微小汚染物
の除去に際し、前記欠点を改善し、均一な高い洗浄効果
が得られる超音波洗浄装置を提供することである。It is an object of the present invention to provide an ultrasonic cleaning apparatus which can improve the above-mentioned drawbacks and can obtain a uniform and high cleaning effect when removing extremely small contaminants attached to a semiconductor substrate.
［発明の構成］ （課題を解決するための手段とその作用） 本発明の超音波洗浄装置は、半導体基板を洗浄液に浸
漬して表面洗浄する装置において、洗浄槽の底部に振動
面が水平面から傾けて設けられた振動板をもつ超音波振
動子を有し、該超音波振動子の発振周波数が800kHzない
し2000kHzの周波数帯域に属するとともに、洗浄槽内の
洗浄液に浸漬される被洗浄半導体基板直下の洗浄槽底部
に洗浄液供給口が設けられ、該洗浄液供給口より流入し
た洗浄液が洗浄槽上部より放流されることを特徴とする
ものである。[Structure of the Invention] (Means for Solving the Problem and Its Action) The ultrasonic cleaning apparatus of the present invention is an apparatus for cleaning a surface of a semiconductor substrate by immersing the semiconductor substrate in a cleaning liquid. An ultrasonic vibrator having a tilted vibration plate is provided, and the oscillation frequency of the ultrasonic vibrator belongs to a frequency band of 800 kHz to 2000 kHz and is directly under the semiconductor substrate to be cleaned which is immersed in the cleaning liquid in the cleaning tank. A cleaning liquid supply port is provided at the bottom of the cleaning tank, and the cleaning liquid flowing in from the cleaning liquid supply port is discharged from the upper part of the cleaning tank.
振動板の振動面を、水平面に対し所定角度傾けて設け
たことにより、振動板から入射する超音波は、洗浄液と
空気との界面において、入射方向と異なる方向に反射す
るので、定在波の発生を防ぐことができ、半導体基板面
に対する洗浄効果は均一となる。又入射超音波は洗浄液
と空気との界面で一度反射され、弱められてから洗浄槽
の対向する側壁に照射されるので、側壁の汚損劣化を防
止できる。又超音波振動子の傾斜配置により、被洗浄半
導体基板直下の洗浄槽底部に洗浄液供給口を設けること
が可能となる。発振周波数が800kHzないし2000kHzの周
波数帯域に属する超音波振動子を設けたので、その超音
波洗浄作用は、主として粒子加速機構によるもので、前
述のように0.1ないし1.0μｍ程度の極微小汚染物の除去
に対し高い洗浄効果が得られる。By providing the vibration surface of the diaphragm at a predetermined angle with respect to the horizontal plane, the ultrasonic wave incident from the diaphragm is reflected at the interface between the cleaning liquid and air in a direction different from the incident direction, so that the standing wave Generation can be prevented, and the cleaning effect on the semiconductor substrate surface becomes uniform. Further, since the incident ultrasonic waves are once reflected at the interface between the cleaning liquid and the air, weakened, and then applied to the opposite side walls of the cleaning tank, it is possible to prevent the side walls from being damaged and deteriorated. Further, by arranging the ultrasonic transducers at an inclined position, it becomes possible to provide a cleaning liquid supply port at the bottom of the cleaning tank immediately below the semiconductor substrate to be cleaned. Since the ultrasonic oscillator belonging to the frequency band of 800 kHz to 2000 kHz is provided, the ultrasonic cleaning action is mainly due to the particle acceleration mechanism, and as described above, the minute contaminant of about 0.1 to 1.0 μm is used. A high cleaning effect is obtained for removal.
また、被洗浄半導体基板直下の洗浄槽底部に洗浄液供
給口が設けられたから、被洗浄基板の直下から供給され
た洗浄液をほぼ基板表面に沿って流すことが可能とな
り、洗浄液の置換効率が高くなり、より高い洗浄効果が
得られる。Further, since the cleaning liquid supply port is provided at the bottom of the cleaning tank directly below the semiconductor substrate to be cleaned, the cleaning liquid supplied from directly below the substrate to be cleaned can be made to flow almost along the substrate surface, and the replacement efficiency of the cleaning liquid is increased. , A higher cleaning effect can be obtained.
（実施例） 本発明に係る超音波洗浄装置の第１の実施例を第１図に
示す。同図（ａ）において、半導体基板５をテフロン製
キャリア10に収納し、キャリアホルダ11により、洗浄槽
21の底から約8cm離して浮かせて洗浄液24内に浸漬す
る。洗浄槽の底部に、振動板22aを含む超音波振動子23a
及び振動板22bを含む超音波振動子23bを設け、振動板22
aの振動面（板面と同じ）は水平面とθ１＝30゜傾け、
又振動板22bの振動面は水平面とθ２＝９゜傾け、それ
ぞれ洗浄槽の中心から約3cmずらして設ける。２つの超
音波振動子23a及び23bは、いずれもその発振周波数は95
0kHzで出力500Wである。半導体基板の直下の洗浄槽底部
に洗浄液（純水）供給口26を設ける。同図（ｂ）は、同
図（ａ）に示す供給口26のＸ−Ｘ′線断面図である。洗
浄液供給口26は、口径1.5cmの円孔が十字形に５つ設け
られたもので、圧力1.5kg/cm2、流量５/minで純水が
供給されている。洗浄液供給口26から流入した純水は、
従来技術欄で説明した第８図装置におけると同様に、洗
浄槽上部より放流される。この状態で10分間半導体基板
を浸して洗浄する。(Embodiment) A first embodiment of the ultrasonic cleaning apparatus according to the present invention is shown in FIG. 1A, a semiconductor substrate 5 is housed in a Teflon carrier 10 and a cleaning tank is
Immerse it in the cleaning liquid 24 by floating it about 8 cm away from the bottom of 21. An ultrasonic transducer 23a including a vibration plate 22a is provided at the bottom of the cleaning tank.
And an ultrasonic transducer 23b including a vibration plate 22b are provided.
The vibration surface of a (same as the plate surface) is inclined with the horizontal plane by θ 1 = 30 °,
Further, the vibrating surface of the vibrating plate 22b is inclined by θ 2 = 9 ° with respect to the horizontal plane, and each is displaced by about 3 cm from the center of the cleaning tank. Each of the two ultrasonic transducers 23a and 23b has an oscillation frequency of 95.
Output is 500W at 0kHz. A cleaning liquid (pure water) supply port 26 is provided at the bottom of the cleaning tank immediately below the semiconductor substrate. FIG. 4B is a cross-sectional view taken along line XX ′ of the supply port 26 shown in FIG. The cleaning liquid supply port 26 is provided with five circular holes having a diameter of 1.5 cm in a cross shape, and pure water is supplied at a pressure of 1.5 kg / cm 2 and a flow rate of 5 / min. Pure water flowing from the cleaning liquid supply port 26 is
The water is discharged from the upper portion of the cleaning tank as in the apparatus shown in FIG. In this state, the semiconductor substrate is dipped for 10 minutes for cleaning.
第２図は、本発明の超音波洗浄装置の第２の実施例を
示したものである。本実施例は洗浄槽31の底部の一方の
側にのみ振動板32を含む超音波振動子33を設けたことが
第１実施例の装置と異なり、他の条件は第１実施例とほ
ぼ同一である。即ち振動板32の振動面（板面と同じ）は
水平面とθ３＝30゜傾けて配置され、超音波振動子33の
発振周波数は950kHzで出力500Wである。又半導体基板５
の直下の洗浄槽底部に純水供給口36が設けられる。FIG. 2 shows a second embodiment of the ultrasonic cleaning apparatus of the present invention. This embodiment is different from the first embodiment in that the ultrasonic vibrator 33 including the vibrating plate 32 is provided only on one side of the bottom of the cleaning tank 31, and other conditions are almost the same as those of the first embodiment. Is. That is, the vibrating surface of the vibrating plate 32 (same as the plate surface) is disposed at an angle of θ 3 = 30 ° with respect to the horizontal plane, and the oscillation frequency of the ultrasonic vibrator 33 is 950 kHz and the output is 500 W. Also semiconductor substrate 5
A pure water supply port 36 is provided at the bottom of the cleaning tank immediately below.
第３図は、本発明の参考例装置を示すものである。即
ちこの装置は、洗浄槽41の底部のほぼ全面で覆うよう
に、振動板42を含む超音波振動子43を設け、振動板42の
振動面を水平面とθ４＝13゜傾けて配置したものであ
る。従って純水供給口46は洗浄槽41の側壁に設けられ
る。FIG. 3 shows a reference example device of the present invention. That is, in this apparatus, the ultrasonic vibrator 43 including the vibrating plate 42 is provided so as to cover almost the entire bottom of the cleaning tank 41, and the vibrating surface of the vibrating plate 42 is disposed at an angle of θ 4 = 13 ° with respect to the horizontal plane. Is. Therefore, the pure water supply port 46 is provided on the side wall of the cleaning tank 41.
試行結果によれば、振動板の振動面の水平面からの傾
きは、３度ないし45度であることが望ましい。即ち傾き
が３度より小さい場合には定在波の発生防止作用、又傾
きが45度を超える場合には入射超音波の直接照射による
洗浄槽側壁の劣化防止作用がそれぞれ損われるおそれが
ある。又洗浄液の供給圧力等は、半導体基板に付着する
極微小汚染物の洗浄効果及びコストを含む生産条件等か
ら試行により決定され、その圧力は0.7ないし2.0kg/c
m2、流量は３ないし10/minであることが望ましい。According to the results of the trial, it is desirable that the inclination of the vibration surface of the diaphragm from the horizontal plane be 3 degrees to 45 degrees. That is, if the inclination is less than 3 degrees, the effect of preventing the generation of standing waves may be impaired, and if the inclination exceeds 45 degrees, the effect of preventing the side wall of the cleaning tank from being deteriorated by the direct irradiation of the incident ultrasonic waves may be impaired. The supply pressure of the cleaning solution is determined by trial from the cleaning conditions of the extremely minute contaminants adhering to the semiconductor substrate and the production conditions including the cost. The pressure is 0.7 to 2.0 kg / c.
m 2 and the flow rate are preferably 3 to 10 / min.
次に本発明の効果を検証する実験データの一例とし
て、半導体基板上に作成したMOSキャパシターの酸化膜
耐圧試験結果について説明する。Next, as an example of the experimental data for verifying the effect of the present invention, the oxide film breakdown voltage test result of the MOS capacitor formed on the semiconductor substrate will be described.
ゲート酸化膜形成工程前の洗浄処理として、本発明の
第１実施例の装置を用いたものと、同一周波数、同一出
力で第９図に示す従来装置を用いて洗浄したものとを比
較した。即ち上記の洗浄処理をした２種類の基板主面に
それぞれ膜厚150Åの酸化膜を形成したのち、ゲート電
極として不純物をドープした膜厚4000Å、シート抵抗20
Ω／□、面積10mm2のポリシリコン膜を積層して、MOSキ
ャパシターを作成した。基板とゲート電極との間に電圧
を印加し酸化膜の耐圧を測定した。As a cleaning treatment before the gate oxide film forming step, a comparison was made between the cleaning using the apparatus of the first embodiment of the present invention and the cleaning using the conventional apparatus shown in FIG. 9 at the same frequency and the same output. That is, an oxide film having a film thickness of 150 Å is formed on each of the two types of substrate main surfaces that have been subjected to the above-described cleaning treatment, and then an impurity-doped film thickness of 4000 Å and a sheet resistance of 20
A MOS capacitor was formed by laminating a polysilicon film of Ω / □ and an area of 10 mm 2 . A withstand voltage of the oxide film was measured by applying a voltage between the substrate and the gate electrode.
酸化膜の電界が8MV/cm以下で破壊したキャパシターの
基板面内での分布を第４図及び第５図に示す。なお×印
は破壊したキャパシターチップを示す。従来装置を用い
て洗浄したキャパシターの結果を示した第４図では、32
チップ中８チップが8MV/cm以下の電界で破壊したのに対
し、本発明の第１の実施例の装置で洗浄した結果を示す
第５図では、32チップのうち１チップが破壊しただけ
で、本発明の装置の洗浄効果が従来装置に比し、優れて
いることがわかる。FIGS. 4 and 5 show the distribution in the substrate surface of the capacitor, which was destroyed when the electric field of the oxide film was 8 MV / cm or less. The mark x indicates a broken capacitor chip. In Fig. 4, which shows the result of the capacitor washed using the conventional device, 32
While 8 of the chips were destroyed by an electric field of 8 MV / cm or less, in FIG. 5 showing the result of cleaning by the apparatus of the first embodiment of the present invention, only one of 32 chips was destroyed. It can be seen that the cleaning effect of the device of the present invention is superior to that of the conventional device.
次に、本発明の第１実施例の装置と従来の第９図に示
す装置とで、それぞれ複数枚の基板を洗浄し、基板表面
上の微粒子除去率を調べた結果の一例を第６図に示す。
同図の○印は平均除去率（％）を、又上下の線分はその
変動範囲を示す。Next, FIG. 6 shows an example of a result obtained by cleaning a plurality of substrates with the apparatus of the first embodiment of the present invention and the apparatus shown in FIG. Shown in.
In the figure, the circles indicate the average removal rate (%), and the upper and lower line segments indicate the fluctuation range.
本発明により、基板表面上の微粒子除去率は格段に向
上し、前記第４図、第５図の結果が裏付けられた。次に
本発明の第１実施例の装置と従来の第９図に示す装置と
を、薬液（HCl）洗浄後の純水リンス（rinse、すすぎ）
に用いた場合の、洗浄液の比抵抗の回復時間を測定した
結果を第７図に示す。同図において、横軸は純水リンス
時間（分）を、縦軸は純水洗浄液の比抵抗（ＭΩ・cm）
値を示す。実曲線ａは本発明の、又破線の曲線ｂは従来
のそれぞれの装置を使用した場合の結果を示す。同図に
よれば比抵抗の回復時間は従来約16分間必要としたもの
が本発明では約10分間に短縮された。According to the present invention, the removal rate of fine particles on the substrate surface is remarkably improved, and the results of FIGS. 4 and 5 are supported. Next, the apparatus according to the first embodiment of the present invention and the conventional apparatus shown in FIG. 9 are rinsed with pure water after cleaning with a chemical solution (HCl).
FIG. 7 shows the results obtained by measuring the recovery time of the specific resistance of the cleaning liquid when used in Example 1. In the figure, the horizontal axis represents the pure water rinsing time (minutes), and the vertical axis represents the specific resistance (MΩ · cm) of the pure water cleaning liquid.
Indicates a value. The solid curve a shows the result when the present invention is used, and the broken line curve b shows the result when each conventional apparatus is used. According to the figure, the specific resistance recovery time required about 16 minutes in the past, but was shortened to about 10 minutes in the present invention.
［発明の効果］ 本発明の超音波洗浄装置では、振動板を水平面に対
し、所定角度傾けて設置したことにより、定在液の発生
は無くなり、半導体基板面に対する洗浄効果の不均一性
を改善することができ、又入射超音波は洗浄液と空気と
の界面において反射し、その強度が弱められた後、洗浄
槽の側壁を照射するので、側壁の劣化は大幅に改善さ
れ、汚染物の発生は防止される。又超音波振動子の発振
周波数を800kHzないし2000kHzとしたことにより、洗浄
作用は主として粒子加速機構によるものとなり、0.1な
いし1.0μｍ程度の極微小汚染物の除去効率は高くな
る。又本発明の装置においては、振動板を傾斜配置した
ので半導体基板の真下から洗浄液を供給することがで
き、洗浄液の置換効率は高められ高い洗浄効果が得られ
る。[Effect of the Invention] In the ultrasonic cleaning apparatus of the present invention, the vibration plate is installed at a predetermined angle with respect to the horizontal plane, thereby eliminating the generation of the standing liquid and improving the non-uniformity of the cleaning effect on the semiconductor substrate surface. The incident ultrasonic waves are reflected at the interface between the cleaning liquid and the air, and the intensity of the ultrasonic waves is reduced. Then, the irradiation of the ultrasonic waves irradiates the side wall of the cleaning tank. Is prevented. Further, by setting the oscillation frequency of the ultrasonic vibrator to 800 kHz to 2000 kHz, the cleaning action is mainly performed by the particle acceleration mechanism, and the removal efficiency of ultra-fine contaminants of about 0.1 to 1.0 μm is increased. Further, in the apparatus of the present invention, since the vibrating plate is arranged so as to be inclined, the cleaning liquid can be supplied from directly below the semiconductor substrate, the replacement efficiency of the cleaning liquid can be enhanced, and a high cleaning effect can be obtained.
本発明により、半導体基板に付着する極微小汚染物の
除去に際して、従来装置の欠点は改善され、均一な高い
洗浄効果が得られる超音波洗浄装置を提供することがで
きた。According to the present invention, when removing ultra-fine contaminants adhering to a semiconductor substrate, the disadvantages of the conventional device are improved, and an ultrasonic cleaning device capable of obtaining a uniform and high cleaning effect can be provided.
第１図（ａ）は、本発明の超音波洗浄装置の第１実施例
の構成の概要を説明するための模式図、同図（ｂ）は洗
浄液供給口の拡大断面図、第２図は、本発明の超音波洗
浄装置の第２実施例の構成の概要を説明するための模式
図、第３図は、本発明の参考例装置の構成を説明するた
めの模式図、第４図及び第５図は、それぞれ従来装置及
び本発明の装置を用いて作成されたMOSキャパシターの
酸化膜耐圧試験結果の半導体基板面内分布図、第６図は
基板表面上の微粒子除去率に関する本発明及び従来装置
の比較図、第７図は純水リンス時の比抵抗回復特性に関
する本発明及び従来装置の比較図、第８図ないし第10図
はそれぞれ従来の超音波洗浄装置の構成の概要を説明す
るための模式図である。 1,21,31,41……洗浄槽、2,12,22a,22b,32,42……振動
板、3,13,23a,23b,33,43……超音波振動子、4,24,34,44
……洗浄液、５……半導体基板、6,26,36,46……洗浄液
供給口、θ1,θ2,θ3,θ４……振動板（振動面）の水平
面からの傾き。FIG. 1A is a schematic diagram for explaining the outline of the configuration of a first embodiment of the ultrasonic cleaning apparatus of the present invention, FIG. 1B is an enlarged sectional view of a cleaning liquid supply port, and FIG. FIG. 3 is a schematic diagram for explaining the outline of the configuration of the second embodiment of the ultrasonic cleaning apparatus of the present invention, and FIG. 3 is a schematic diagram for explaining the configuration of the reference example apparatus of the present invention; FIG. 5 is an in-plane distribution diagram of the oxide film breakdown voltage test results of a MOS capacitor manufactured using the conventional device and the device of the present invention, and FIG. 6 is the present invention concerning the removal rate of fine particles on the substrate surface. FIG. 7 is a comparative diagram of a conventional device, FIG. 7 is a comparative diagram of the present invention and a conventional device regarding a specific resistance recovery characteristic at the time of rinsing with pure water, and FIGS. 8 to 10 are schematic views of the configuration of a conventional ultrasonic cleaning device. It is a schematic diagram for doing. 1,21,31,41 …… Cleaning tank, 2,12,22a, 22b, 32,42 …… Diaphragm, 3,13,23a, 23b, 33,43 …… Ultrasonic vibrator, 4,24, 34,44
... cleaning liquid, 5 ... semiconductor substrate, 6, 26, 36, 46 ... cleaning liquid supply port, [theta] 1 , [theta] 2 , [theta] 3 , [theta] 4 ... inclination of the diaphragm (vibration surface) from the horizontal plane.
フロントページの続き (56)参考文献 特開 昭63−58840（ＪＰ，Ａ) 特開 昭62−286231（ＪＰ，Ａ) 特開 昭60−72233（ＪＰ，Ａ) 特開 昭64−18229（ＪＰ，Ａ) 特開 昭60−78680（ＪＰ，Ａ) 実開 昭63−153530（ＪＰ，Ｕ) 実開 昭62−13589（ＪＰ，Ｕ)Continuation of the front page (56) Reference JP 63-58840 (JP, A) JP 62-286231 (JP, A) JP 60-72233 (JP, A) JP 64-18229 (JP , A) JP 60-78680 (JP, A) Actually opened 63-153530 (JP, U) Actually opened 62-13589 (JP, U)
Claims (1)
る装置において、洗浄槽の底部に振動面が水平面から傾
けて設けられた振動板をもつ超音波振動子を有し、該超
音波振動子の発振周波数が800kHzないし2000kHzの周波
数帯域に属するとともに、洗浄槽内の洗浄液に浸漬され
る被洗浄半導体基板直下の洗浄槽底部に洗浄液供給口が
設けられ、該洗浄液供給口より流入した洗浄液が洗浄槽
上部より放流されることを特徴とする超音波洗浄装置。1. An apparatus for cleaning a surface by immersing a semiconductor substrate in a cleaning liquid, comprising: an ultrasonic vibrator having a vibrating plate provided at the bottom of a cleaning tank with a vibrating surface inclined from a horizontal plane. The oscillation frequency of the child belongs to the frequency band of 800 kHz to 2000 kHz, and a cleaning liquid supply port is provided at the bottom of the cleaning tank directly below the semiconductor substrate to be cleaned that is immersed in the cleaning liquid in the cleaning tank, and the cleaning liquid flowing from the cleaning liquid supply port is An ultrasonic cleaning device which is discharged from the upper part of the cleaning tank.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63182493A JP2669655B2 (en) | 1988-07-21 | 1988-07-21 | Ultrasonic cleaning equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63182493A JP2669655B2 (en) | 1988-07-21 | 1988-07-21 | Ultrasonic cleaning equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0232525A JPH0232525A (en) | 1990-02-02 |
| JP2669655B2 true JP2669655B2 (en) | 1997-10-29 |
Family
ID=16119251
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63182493A Expired - Fee Related JP2669655B2 (en) | 1988-07-21 | 1988-07-21 | Ultrasonic cleaning equipment |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2669655B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100475774B1 (en) * | 2002-11-27 | 2005-03-10 | (주)울텍 | The Method and apparatus for Removal of Bubbles on the Substrate by Ultrasonic Waves |
| KR100800174B1 (en) | 2006-10-20 | 2008-02-01 | 한국기계연구원 | Wafer cleaning module using megasonic |
| EP2515323B1 (en) * | 2011-04-21 | 2014-03-19 | Imec | Method and apparatus for cleaning semiconductor substrates |
| CN114713561A (en) * | 2022-04-20 | 2022-07-08 | 新疆八一钢铁股份有限公司 | Cleaning method for quartz combustion tube of infrared carbon-sulfur analyzer |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6072233A (en) * | 1983-09-28 | 1985-04-24 | Toshiba Corp | Washing device for semiconductor wafer |
| JPH0691064B2 (en) * | 1986-06-05 | 1994-11-14 | 株式会社プレテツク | Cleaning equipment |
| JPH0695509B2 (en) * | 1986-08-29 | 1994-11-24 | ホ−ヤ株式会社 | Cleaning method and its apparatus |
| JPS63153530U (en) * | 1987-03-30 | 1988-10-07 | ||
| JPS6418229A (en) * | 1987-07-14 | 1989-01-23 | Oki Electric Ind Co Ltd | Super-ultrasonic cleaning device |
-
1988
- 1988-07-21 JP JP63182493A patent/JP2669655B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0232525A (en) | 1990-02-02 |
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