JPH02257627A - Method and apparatus for polishing of semiconductor wafer - Google Patents
Method and apparatus for polishing of semiconductor waferInfo
- Publication number
- JPH02257627A JPH02257627A JP1078977A JP7897789A JPH02257627A JP H02257627 A JPH02257627 A JP H02257627A JP 1078977 A JP1078977 A JP 1078977A JP 7897789 A JP7897789 A JP 7897789A JP H02257627 A JPH02257627 A JP H02257627A
- Authority
- JP
- Japan
- Prior art keywords
- polishing
- tank
- polishing liquid
- semiconductor wafer
- attached
- 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
- 238000005498 polishing Methods 0.000 title claims abstract description 209
- 238000000034 method Methods 0.000 title claims abstract description 17
- 239000004065 semiconductor Substances 0.000 title claims description 49
- 239000007788 liquid Substances 0.000 claims abstract description 91
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 68
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 21
- 239000008119 colloidal silica Substances 0.000 claims abstract description 17
- 235000012431 wafers Nutrition 0.000 claims description 50
- 239000004744 fabric Substances 0.000 claims description 14
- 239000002904 solvent Substances 0.000 claims description 14
- 239000011550 stock solution Substances 0.000 claims description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 8
- 238000007517 polishing process Methods 0.000 claims description 5
- 239000000243 solution Substances 0.000 claims description 5
- 235000015073 liquid stocks Nutrition 0.000 claims description 3
- 239000002245 particle Substances 0.000 abstract description 11
- 238000009826 distribution Methods 0.000 abstract description 6
- 230000005484 gravity Effects 0.000 description 13
- 238000010586 diagram Methods 0.000 description 6
- 230000007423 decrease Effects 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 239000011362 coarse particle Substances 0.000 description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- HZAXFHJVJLSVMW-UHFFFAOYSA-N 2-Aminoethan-1-ol Chemical compound NCCO HZAXFHJVJLSVMW-UHFFFAOYSA-N 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 230000001133 acceleration Effects 0.000 description 2
- 238000004220 aggregation Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000000691 measurement method Methods 0.000 description 2
- 230000003746 surface roughness Effects 0.000 description 2
- 235000010724 Wisteria floribunda Nutrition 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000002612 dispersion medium Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000002609 medium Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 229920005749 polyurethane resin Polymers 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 235000011121 sodium hydroxide Nutrition 0.000 description 1
- 238000002604 ultrasonography Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Landscapes
- Grinding-Machine Dressing And Accessory Apparatuses (AREA)
- Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
- Mechanical Treatment Of Semiconductor (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本願発明は、シリコン等からなる半導体ウェーハの研磨
方法及び装置に関する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method and apparatus for polishing semiconductor wafers made of silicon or the like.
（従来の技術）
ＬＳＩ等の大規模集積回路を製作する材料である半導体
ウェーハは、最終鏡面仕上を行う研磨工程において、そ
の最終品質が決定される。(Prior Art) The final quality of semiconductor wafers, which are materials for manufacturing large-scale integrated circuits such as LSIs, is determined in a polishing process for final mirror finishing.
上記研磨工程では、−船釣にメカニカルポリッシングと
呼ばれる研磨手法が採用されている。即ち、５〜３００
ｍｍ程度の粒径な有するＳｉＯ□粒子を苛性ソーダ、ア
ンモニア及びエタノールアミン等のアルカリ溶液に懸濁
させてＰＨを９〜１２程度に調整した、いわゆるコロイ
ダルシリカから成る研磨液と、ポリウレタン樹脂等から
成る研磨布とを用いて研磨を行う。In the above polishing process, a polishing method called mechanical polishing is adopted for boat fishing. i.e. 5-300
A polishing liquid made of so-called colloidal silica, in which SiO□ particles with a particle size of about mm are suspended in an alkaline solution such as caustic soda, ammonia, and ethanolamine, and the pH is adjusted to about 9 to 12, and a polyurethane resin. Polishing is performed using a polishing cloth.
そして上記研磨工程は、−船釣に第７図に示すように、
１次、２次、３次の３段階から成る。具体的には、１次
研磨では、前工程で生じた歪を除去することを目的とし
て、高硬度研磨布により５〜２０ｐｍ程度の研磨を行う
。そして２次研磨では、上記１次研磨で生じた歪を除去
することを目的として中硬度研磨布により０゜？−５ｐ
ｍ＋程度の研磨を行い、最後の３次研磨では、ウェーハ
表面に残っている曇り（ヘイズ）を除去することを目的
として、低硬度研磨布により０．０１〜１．０μ、ｍ程
。度の研磨を行い、超精密な半導体ウェーハを得るので
ある。例えば、５インチウェーハの場合、全厚さむら（
ＴＴＶ）が３〜４ｐｍ、面粗さが１〜１０人程度被着精
密な半導体ウェーハとなされる。The above-mentioned polishing process is performed as shown in FIG.
It consists of three stages: primary, secondary, and tertiary. Specifically, in the primary polishing, polishing is performed to a depth of about 5 to 20 pm using a high-hardness polishing cloth for the purpose of removing distortion caused in the previous step. In the secondary polishing, a medium hardness polishing cloth is used to remove the distortion caused by the primary polishing. -5p
Polishing is performed to a depth of approximately m+, and in the final tertiary polishing, a polishing depth of approximately 0.01 to 1.0 μm is performed using a low hardness polishing cloth for the purpose of removing haze remaining on the wafer surface. By performing a high degree of polishing, ultra-precise semiconductor wafers are obtained. For example, in the case of a 5-inch wafer, the total thickness unevenness (
The resulting semiconductor wafer has a surface roughness of about 1 to 10 pm (TTV) of 3 to 4 pm and a surface roughness of about 1 to 10 pm.
そして上記１〜３次研磨において上述のコロイダルシリ
カを含む高価な研磨液が使用されているのであり、単位
時間当り多量に研磨液を使用する１次、２次研磨では、
通常、研磨液はリサイクル使用され、所定の寿命到達時
に交換される。In the first to third polishing described above, an expensive polishing liquid containing the above-mentioned colloidal silica is used, and in the first and second polishing, a large amount of polishing liquid is used per unit time.
Typically, the polishing fluid is recycled and replaced when it reaches a predetermined lifespan.
第６図は従来の１次又は２次研磨の研磨装置の概念図で
あって、該図において、１は研磨機であり、該研磨機１
の座２上に研磨布３が置かれる。FIG. 6 is a conceptual diagram of a conventional polishing apparatus for primary or secondary polishing, and in this figure, 1 is a polishing machine;
A polishing cloth 3 is placed on the seat 2.
４は座２の天井部から垂下せしめられた回転軸であり、
該回転軸４の下端に半導体ウェーハ５が支持されている
。研磨液６はタンク７に収められ、該タンク７から供給
配管８によって座２の上面に供給され、研磨使用された
研磨液６は、戻り配管９によって座２から上記タンク７
へ戻される。そして上記供給配管８の中途部適所には、
供給ポンプ１０及びフィルタ１１が付設されている。4 is a rotating shaft hanging from the ceiling of seat 2;
A semiconductor wafer 5 is supported at the lower end of the rotating shaft 4. The polishing liquid 6 is stored in a tank 7, and is supplied from the tank 7 to the upper surface of the seat 2 through a supply pipe 8. The polishing liquid 6 used for polishing is returned from the seat 2 to the tank 7 through a return pipe 9.
be returned to. At a suitable midway point in the supply pipe 8,
A feed pump 10 and a filter 11 are attached.
（発明が解決しようとする課題）
ところで従来の半導体ウェーハの研磨には次のような問
題点がある。(Problems to be Solved by the Invention) Conventional polishing of semiconductor wafers has the following problems.
研磨は通常、研磨剤を使用する実研磨と、その後、水を
使用した水リンスとからなり、その研磨剤と水との切換
えが不十分であつた場合、研磨液に水が混入することが
あり、この場合にコロイダルシリカの含有濃度（以下、
「研磨液濃度」と称する）が小さくなって、単位時間当
りの研磨スピードが低下する。Polishing usually consists of actual polishing using an abrasive and then rinsing using water. If the switching between the abrasive and water is insufficient, water may get mixed into the polishing solution. In this case, the content concentration of colloidal silica (hereinafter referred to as
(referred to as "polishing liquid concentration") becomes smaller, and the polishing speed per unit time decreases.
また、半導体ウェーハが研磨されることによって生じた
微少シリカが、研磨液中のコロイダルシリカに吸着され
、コロイダルシリカの凝集が起り、研磨液の研磨能力が
使用寿命に比例して低下し、第４図に示すように、単位
時間当りの研磨スピードが低下する。In addition, microscopic silica generated when semiconductor wafers are polished is adsorbed by colloidal silica in the polishing solution, causing aggregation of the colloidal silica, and the polishing ability of the polishing solution decreases in proportion to the service life. As shown in the figure, the polishing speed per unit time decreases.
上記コロイダルシリカの凝集は、研磨液が新液である場
合と重液である場合とを比較して見れば一目瞭然である
。The aggregation of colloidal silica is clearly seen when comparing the case where the polishing liquid is a fresh liquid and the case where the polishing liquid is a heavy liquid.
すなわち、第５図は、研磨液が新液である場合の粒径分
布と重液である場合の粒径分布を対比して示すグラフで
、新液である場合は、コロイダルシリカの粒径が４ＯＮ
Ｍ〜２０ＯＮＭの範囲であるのに対し、重液である場合
は、４ＯＮＭ〜９０ＯＮＭの範囲である。なお、各粒径
の量は左縦軸の数値で読み取る棒グラフで示し、一定粒
径以下の累積量は左縦軸の数値で読み取る線グラフ（白
抜きは新液、塗りつぶしは重液）で示している。In other words, Fig. 5 is a graph showing a comparison of the particle size distribution when the polishing liquid is a fresh liquid and the particle size distribution when it is a heavy liquid. 4ON
The range is from M to 20ONM, while for heavy liquids it is from 4ONM to 90ONM. The amount of each particle size is shown in a bar graph that can be read by the numerical value on the left vertical axis, and the cumulative amount below a certain particle size is shown in a line graph that can be read by the numerical value on the left vertical axis (white areas indicate new liquid, filled areas indicate heavy liquid). ing.
なお、第４図は、研磨液のリサイクル回数を横軸に採り
、また単位時間当りの研磨スピードを縦軸に採ったもの
である。In FIG. 4, the horizontal axis represents the number of times the polishing liquid is recycled, and the vertical axis represents the polishing speed per unit time.
更に、従来の半導体ウェーハの研磨では、第６図に示す
ように、フィルタ１１で凝集粗大シリカ粒子又はその他
の粗大粒子を研磨液６から分離するようにしていたが、
上記フィルタ１１の分離能力が十分でなく、研磨進行中
の半導体ウェーハ５に研磨キズを生じさせることが多か
った。Furthermore, in conventional semiconductor wafer polishing, aggregated coarse silica particles or other coarse particles are separated from the polishing liquid 6 using a filter 11, as shown in FIG.
The separation ability of the filter 11 was not sufficient, and polishing scratches were often caused on the semiconductor wafer 5 during polishing.
本願発明は、上記問題点を解決することを課題としてな
されたものである。The present invention has been made with the object of solving the above-mentioned problems.
（課題を解決するための手段）
すなわち、第１の発明は、半導体ウェーハを研磨布で研
磨する際、研磨面に対しコロダルシリカを含有する研磨
液を循環使用する半導体ウェーハの研磨方法において、
研磨液の循環径路途中に遠心分離器を付設し、該遠心分
離器により凝集粗大シリカを除去しつつ研磨液を循環使
用する半導体ウェーハの研磨方法であり、第２の発明は
、研磨機と、研磨液を貯留するタンクと、循環経路を設
けるべく前記研磨機とタンク間に付設された配管と、該
配管の途中部に付設された供給ポンプとを具備する半導
体ウェーハの研磨装置において、前記タンクに遠心分離
器を付設した半導体ウェーハの研磨装置であり、第３の
発明は、半導体ウェー八を研磨布で研磨する際、研磨面
に対しコロイダルシリカを含有する研磨液を循環使用す
る半導体ウェーハの研磨方法において、研磨面に供給す
べき研磨液の濃度を計測し、該計測値に基いて高濃度の
研磨原液及び水等溶媒を、適宜供給することにより研磨
面に供給すべき研磨液の濃度を一定に保持し、研磨布で
半導体ウェーハを研磨する半導体ウェーハの研磨方法で
あり、第４の発明は、研磨機と、研磨液を貯留するタン
クと、循環経路を設けるべく前記研磨機とタンク間に付
設された配管と、該配管の中途部に付設された供給ポン
プとを具備する半導体ウェーハの研磨装置において、前
記タンク内に超音波伝播速度計測器を配設する一方、タ
ンクに研磨液の原液タンク及び溶媒タンクを付設し、こ
れら再供給タンクに比例弁を取付け、更に超音波伝播速
度計測器の計測値を演算して前記比例弁を制御する制動
装置を備えさせた半導体ウェーハの研磨装置であり、第
５の発明は、研磨機と、研磨液を貯留するタンクと、循
環経路を設けるべく前記研磨機とタンク間に付設された
配管と、該配管の中途部に付設された供給ポンプとを具
備する半導体ウェーハの研磨装置において、前記タンク
内にディスプレーサを配設する一方、タンクに研磨液の
原液タンク及び溶媒タンクを付設し、これら再供給タン
クに比例弁を取付け、更にディスプレーサの受ける浮力
の計測値を演算して前記比例弁を制御する制動装置を備
えさせた半導体ウェーハの研磨装置であり、第６Ｑ発明
は、半導体ウェー八を研磨布で研磨する際、研磨面に対
しコロイダルシリカを含有する研磨液を循環使用する半
導体ウェーハの研磨方法において、研磨面に供給すべき
研磨液の濃度を計測し、該計測値に基いて高濃度の研磨
原液及び水等溶媒を、適宜供給することにより研磨面に
供給すべき研磨液の濃度を一定に保持し、更に、研磨液
の循環経路途中に遠心分離装置を付設し、該遠心分離装
置により凝集粗大シリカを除去しつつ研磨液を循環使用
して、研磨布で半導体ウェーハを研磨する半導体ウェー
ハの研磨方法である。(Means for Solving the Problem) That is, the first invention is a method for polishing a semiconductor wafer, in which a polishing liquid containing corodal silica is circulated to the polishing surface when polishing the semiconductor wafer with a polishing cloth,
A semiconductor wafer polishing method is provided with a centrifugal separator in the middle of a polishing liquid circulation path, and the polishing liquid is circulated and used while removing aggregated coarse silica with the centrifugal separator, and the second invention is a polishing machine; A semiconductor wafer polishing apparatus comprising a tank for storing a polishing liquid, a pipe attached between the polisher and the tank to provide a circulation path, and a supply pump attached to an intermediate part of the pipe, wherein the tank A semiconductor wafer polishing apparatus is provided with a centrifugal separator attached to the semiconductor wafer. In the polishing method, the concentration of the polishing liquid to be supplied to the polishing surface is determined by measuring the concentration of the polishing liquid to be supplied to the polishing surface, and appropriately supplying a high concentration polishing stock solution and a solvent such as water based on the measured value. A fourth invention is a semiconductor wafer polishing method for polishing a semiconductor wafer with a polishing cloth while holding the polishing liquid at a constant level, and a fourth invention is a method for polishing a semiconductor wafer, in which a polishing machine, a tank for storing polishing liquid, and a polishing machine and a tank for providing a circulation path are provided. In a polishing apparatus for semiconductor wafers, which includes a pipe attached between the pipes and a supply pump attached to the middle part of the pipe, an ultrasonic propagation velocity measuring device is disposed in the tank, and a polishing liquid is placed in the tank. polishing of a semiconductor wafer, which is equipped with a stock solution tank and a solvent tank, a proportional valve attached to these resupply tanks, and a braking device that calculates the measured value of an ultrasonic propagation velocity measuring device and controls the proportional valve. A fifth invention is an apparatus, and a fifth invention includes a polishing machine, a tank for storing polishing liquid, a pipe attached between the polishing machine and the tank to provide a circulation path, and a supply attached to a midway part of the pipe. In the polishing apparatus for semiconductor wafers, which is equipped with a pump, a displacer is disposed in the tank, a polishing liquid stock tank and a solvent tank are attached to the tank, a proportional valve is attached to these re-supply tanks, and a displacer pump is provided. A semiconductor wafer polishing apparatus is provided with a braking device that controls the proportional valve by calculating the measured value of the buoyant force received, and the sixth Q invention is a semiconductor wafer polishing apparatus that is provided with a braking device that controls the proportional valve by calculating the measured value of the buoyant force received. In a semiconductor wafer polishing method that recirculates a polishing liquid containing silica, the concentration of the polishing liquid to be supplied to the polishing surface is measured, and a high concentration polishing stock solution and a solvent such as water are appropriately supplied based on the measured value. By doing this, the concentration of the polishing liquid to be supplied to the polishing surface is maintained constant, and furthermore, a centrifugal separator is installed in the middle of the circulation path of the polishing liquid, and the centrifugal separator removes aggregated coarse silica while discharging the polishing liquid. This is a semiconductor wafer polishing method in which semiconductor wafers are polished with a polishing cloth that is used in circulation.
より具体的に説明すると、−船釣に、研磨に際してリサ
イクル使用（循環使用）されるコロイダルシリカ粒子の
粒径分布は、第５図に示すように、重液の方が、大きい
粒径のコロイダルシリカが多くなる。その理由は、上述
したように、半導体ウェー八が研磨されることによって
生じた微少シリカ（研磨くず）が研磨剤中に吸入され、
その結果凝集粗大シリカ粒子の割合が増加するからであ
る。このとき研磨液の色も乳白色から次第に赤茶色に変
色する。To explain more specifically, - The particle size distribution of colloidal silica particles recycled (circulated) during polishing in boat fishing is as shown in Figure 5. More silica. The reason for this is, as mentioned above, that fine silica (polishing waste) generated when the semiconductor wafer is polished is sucked into the polishing agent.
This is because as a result, the proportion of aggregated coarse silica particles increases. At this time, the color of the polishing liquid gradually changes from milky white to reddish brown.
上記赤茶色状の凝集粗大シリカ粒子は、遠心力場におく
ことによって容易に沈降させることができる。つまり、
球形粗大粒子の沈降速度Ｖは、Ｖ＝２ （ＰＩ−Ｐ、）
ｄ”ｇ／９ｎ。The reddish-brown aggregated coarse silica particles can be easily sedimented by placing them in a centrifugal force field. In other words,
The sedimentation velocity V of spherical coarse particles is V=2 (PI-P,)
d”g/9n.
但しｐ、・・・球形粗大粒子の密度 ｄ・・・球形粗大粒子の半径 ｐｏ・・・分散媒の密度 ｎｏ・・・粘性係数 ｇ・・・遠心力 で表わされる。However, p... Density of spherical coarse particles d...Radius of spherical coarse particles po...Density of dispersion medium no...viscosity coefficient g...Centrifugal force It is expressed as
従って、重力加速度の８０００倍程度以上の遠心力を有
する遠心力場に赤茶色状の凝集粗大シリカ粒子を有する
研磨液を通し、且つその処理時間を適度に設定してやれ
ば凝集粗大シリカ粒子のみを沈降させることができる。Therefore, by passing a polishing solution containing reddish-brown aggregated coarse silica particles through a centrifugal force field with a centrifugal force of about 8000 times or more than the acceleration of gravity, and by setting the processing time appropriately, only the aggregated coarse silica particles will settle. can be done.
また、一定時間内に施される研磨によって均質な半導体
ウェーハを得るためには、常時一定濃度の研磨液を供給
してあげる必要がある。Furthermore, in order to obtain a homogeneous semiconductor wafer by polishing within a certain period of time, it is necessary to constantly supply a polishing liquid with a certain concentration.
ところで、−船釣に、同質のコロイダルシリカを含む研
磨液濃度は、研磨液の比重に比例する。By the way, in boat fishing, the concentration of a polishing liquid containing colloidal silica of the same quality is proportional to the specific gravity of the polishing liquid.
従って、研磨液の比重を算出し、その数値に基いて研磨
液濃度を一定に保持することができる。Therefore, the specific gravity of the polishing liquid can be calculated and the concentration of the polishing liquid can be kept constant based on the calculated value.
上記比重の計測においては、超音波伝播速度計測により
比重を算出する方法、或いはディスプレーサ（浮き）を
利用した直接比重計測法を採用し得る。In measuring the specific gravity, a method of calculating the specific gravity by ultrasonic propagation velocity measurement, or a direct specific gravity measurement method using a displacer (float) can be adopted.
前者は、液体中を伝わる超音波の速さが液体の成分（濃
度）と温度とによって大きく変化する原理を利用して液
体の濃度を計測するもので、具体的には、液体の比重な
Ｐ、体積弾性率をｅ、液体中の超音波の伝播速度なυ、
としたとき、Ｐ＝ｅ／υｘ２
となることを利用したものである。なお、市販の超音波
液体用濃度計としては、例えば、ＦＵＤ−１（商品名：
富士工業株式会社製）等が挙げられる。また、後者は、
ディスプレーサ（浮き）を研磨液中に投入し、ここで受
ける浮力を計測して比重を算出するものである。The former measures the concentration of a liquid by using the principle that the speed of ultrasonic waves traveling through the liquid changes greatly depending on the liquid's components (concentration) and temperature. , the bulk modulus is e, the propagation velocity of ultrasound in the liquid is υ,
This takes advantage of the fact that when , P=e/υx2. In addition, as a commercially available ultrasonic liquid concentration meter, for example, FUD-1 (trade name:
(manufactured by Fuji Kogyo Co., Ltd.), etc. Also, the latter is
A displacer (float) is placed in the polishing liquid, and the buoyant force it receives is measured to calculate the specific gravity.
（作 用）
供給配管に流される研磨液は、研磨機に送られ研磨に供
される。使用された研磨液中には微少なシリカ粒子を供
って戻り配管を通りタンクに戻されるが、やがて上記微
少なシリカ粒子がコロイダルシリカに吸着されて研磨液
中に凝集粗大シリカが生成される。この凝集粗大シリカ
を含む研磨液は上記遠心分離器に通されて、ここで凝集
粗大シリカが除かれる。このようにして凝集粗大シリカ
が除かれると研磨液の濃度が低下するが、研磨液の濃度
低下が検知されると比例弁が開いて研磨原液及び溶媒が
注入され、研磨液の濃度を一定に保持する。かくして、
常時一定粒径以下のコロイダルシリカを含み一定濃度と
なされた研磨液が半導体ウェーハの研磨に再使用される
ことになる。(Function) The polishing liquid flowing into the supply pipe is sent to the polishing machine and used for polishing. The used polishing liquid is returned to the tank through the return pipe with minute silica particles, but eventually the minute silica particles are adsorbed by colloidal silica and aggregated coarse silica is generated in the polishing liquid. . The polishing liquid containing the aggregated coarse silica is passed through the centrifugal separator, where the aggregated coarse silica is removed. When the aggregated coarse silica is removed in this way, the concentration of the polishing liquid decreases, but when a decrease in the concentration of the polishing liquid is detected, the proportional valve opens and the polishing stock solution and solvent are injected to keep the concentration of the polishing liquid constant. Hold. Thus,
A polishing liquid that always contains colloidal silica with a particle size of a certain size or less and has a certain concentration is reused for polishing semiconductor wafers.
（実施例） 以下、本願発明を添付図面に基いて説明する。(Example) Hereinafter, the present invention will be explained based on the accompanying drawings.
第１図は、研磨液の比重測定（換言すれば濃度測定）を
超音波伝播速度計測器にいて行う実施例を示す概念図、
第２図は遠心分離器の拡大断面図、第３図は研磨液の比
重測定（換言すれば濃度測定）をディスプレーサ（浮き
）によって行う実施例を示す概念図であり、これらの図
中、第６図に用いた符号と同一の符号は、同−物若しく
は該当物を示す。FIG. 1 is a conceptual diagram showing an example in which specific gravity measurement (in other words, concentration measurement) of a polishing liquid is performed using an ultrasonic propagation velocity measuring device;
Fig. 2 is an enlarged sectional view of a centrifugal separator, and Fig. 3 is a conceptual diagram showing an embodiment in which specific gravity measurement (in other words, concentration measurement) of polishing liquid is performed using a displacer (float). The same reference numerals as those used in Fig. 6 indicate the same or corresponding items.
第１図及び第３図の実施例図に示すように、タンク７に
は、凝集粗大シリカを除去するために遠心分離器１２が
付設されている。この遠心分離器１２は、第２図に断面
して示す如き構成のもので、１２ａは回転筒、１２ｂは
電動機、１２ｅは軸受を示す。As shown in the embodiment diagrams of FIGS. 1 and 3, a centrifugal separator 12 is attached to the tank 7 to remove aggregated coarse silica. This centrifugal separator 12 has a structure as shown in cross section in FIG. 2, where 12a is a rotating cylinder, 12b is an electric motor, and 12e is a bearing.
更に具体的には、タンク７に分枝供給管１３を枝出しし
てその先端に遠心分離器１２の一端を接続し、更に該遠
心分離器１２の他端に分枝戻り管ｌ４を接続し、この分
枝戻り管１４の他端をタンク７に到らせている。また、
１５は定流量弁で、研磨液６を遠心分離器１２内に送り
込むべく、また、研磨液６の通過時間を所定の時間とな
すべく分枝供給管１３の中途部に設けている。従って、
タンク７内に存する研磨液６は常に遠心分離器１２を通
され、該遠心分離器１２て凝集粗大シリカが分離除去さ
れる。ここで上記遠心分離器１２は重力加速度の８００
０倍以上の遠心力を与え得るものが必要であり、例えば
市販のものではシャープレス（商標名：巴工業株式会社
製）等を採用すればよい。なお、当該遠心分離器１２内
における研磨液６の通過時間は１〜６分間位に設定する
のが好ましい。More specifically, a branch supply pipe 13 is branched out from the tank 7, one end of the centrifugal separator 12 is connected to the tip thereof, and a branch return pipe 14 is further connected to the other end of the centrifugal separator 12. The other end of this branch return pipe 14 reaches the tank 7. Also,
A constant flow valve 15 is provided in the middle of the branch supply pipe 13 in order to send the polishing liquid 6 into the centrifugal separator 12 and to make the passage time of the polishing liquid 6 a predetermined time. Therefore,
The polishing liquid 6 existing in the tank 7 is always passed through a centrifugal separator 12, and the aggregated coarse silica is separated and removed by the centrifugal separator 12. Here, the centrifugal separator 12 has a gravitational acceleration of 800
A material capable of applying a centrifugal force of 0 times or more is required, and for example, a commercially available product such as Sharpless (trade name: manufactured by Tomoe Kogyo Co., Ltd.) may be used. Note that the passage time of the polishing liquid 6 in the centrifugal separator 12 is preferably set to about 1 to 6 minutes.
更に上記タンク７には、タンク７内に研磨原液１６を供
給すべく、送給管１７を備えた原液タンク１８が、そし
て、タンク７内に水等溶媒１９を供給すべく送給管２０
を備えた溶媒タンク２１が付設されている。Furthermore, the tank 7 includes a stock solution tank 18 equipped with a feed pipe 17 for supplying the polishing stock solution 16 into the tank 7, and a feed pipe 20 for supplying a solvent 19 such as water into the tank 7.
A solvent tank 21 is attached.
１７ａ、２０ａは上記供給管１７．２０に設けられた比
例弁であり、研磨原液１６と溶媒１９の送給割合を一定
比率に維持する役割を担っており、これら比例弁１７ａ
、２０ａの作動量は、タンク７内の研磨液６に比重（換
言すれば濃度）によって制御される。17a and 20a are proportional valves provided in the supply pipe 17.20, and have the role of maintaining the feeding ratio of the polishing stock solution 16 and the solvent 19 at a constant ratio, and these proportional valves 17a
, 20a are controlled by the specific gravity (in other words, the concentration) of the polishing liquid 6 in the tank 7.
すなわち、第１図の実施例では、タンク７内の研磨液６
中の超音波伝播速度計測器２２を配設して、この超音波
伝播速度計測器２２によって研磨液６の比重を測定し、
該測定値に基いて制御装置２３により上記比例弁１７ａ
、２０ａの開度を調整している。That is, in the embodiment shown in FIG.
An ultrasonic propagation velocity measuring device 22 is disposed inside, and the specific gravity of the polishing liquid 6 is measured by this ultrasonic propagation velocity measuring device 22,
Based on the measured value, the controller 23 controls the proportional valve 17a.
, 20a are adjusted.
また、第３図の実施例は、いわゆる直接比重測定法であ
って、タンク７内の研磨液６中に、ディスプレーサ２４
（浮き）を配し、該ディスプレーサ２４の受ける浮力を
トルクメータ２５に計測せしめ、上記制動装置２３で比
例弁１７ａ、２０ａの開度を調整している。The embodiment shown in FIG. 3 is a so-called direct specific gravity measurement method, in which the displacer 24 is
A torque meter 25 measures the buoyant force exerted on the displacer 24, and the braking device 23 adjusts the opening degrees of the proportional valves 17a and 20a.
かくして、比例弁１７ａ、２０ａの適正な開度調整によ
りタンク７内の研磨液６の濃度が常時−足保持され、供
給配管８には常に一定濃度の研磨液が送り込まれること
になる。In this way, by appropriately adjusting the opening degrees of the proportional valves 17a and 20a, the concentration of the polishing liquid 6 in the tank 7 is always maintained at a constant level, and a constant concentration of polishing liquid is always fed into the supply pipe 8.
（発明の効果）
以上説明したように、本願発明に依れば、凝集粗大シリ
カを除去してコロイダルシリカ全体の粒度分布を均一化
しているため、研磨キズの発生を未然に防止できると共
に、研磨液の使用寿命を延ばし得る。そして、供給すべ
き研磨液の濃度を一定に保持しているため、半導体ウェ
ーハの研磨スピードを均一化でき、研磨液の交換使用を
可及的に押え得て作業性が向上することができ、更には
従来必要であったフィルターの清掃管理を行わなくて済
む等、多岐に亘る効益を奏するものである。(Effects of the Invention) As explained above, according to the present invention, since the aggregated coarse silica is removed and the particle size distribution of the entire colloidal silica is made uniform, it is possible to prevent the occurrence of polishing scratches and The service life of the liquid can be extended. Since the concentration of the polishing liquid to be supplied is kept constant, the polishing speed of the semiconductor wafer can be made uniform, and the replacement of the polishing liquid can be suppressed as much as possible, improving work efficiency. Furthermore, it provides a wide range of benefits, such as eliminating the need to manage the cleaning of filters, which was conventionally necessary.
第１図は研磨液の比重測定を超音波伝播速度計測器にて
行う実施例を示す概念図、第２図は遠心分離器の拡大断
面図、第３図は研磨液の比重測定をディスプレーサ（浮
き）によって行う実施例を示す概念図、第４図は研磨液
のリサイクル回数と研磨スピードとの関係を示すグラフ
、第５図は研磨液が新液である場合と重液である場合に
おける粒径分布グラフ、第６図は従来の研磨装置の概念
図、第７図は研磨工程のフローチャートである。
１・・・研磨機 ３・・・半導体ウェーハ５・
・・研磨布 ６・・・研磨液７・・・タンク
８・・・供給配管９・・・戻り配管 １
０・・・供給ポンプ１２・・・遠心分離器 １６・・
・研磨原液１７ａ・・・比例弁 １８・・・原液タ
ンク１９・・・溶媒 ２０ａ・・・比例弁２１
・・・溶媒タンク
２２・・・超音波伝播速度測定器
２３・・・制動装置 ２４・・・ディスプレーサ特
許出願人 九州電子金属株式会社Figure 1 is a conceptual diagram showing an example in which the specific gravity of the polishing liquid is measured using an ultrasonic propagation velocity measuring device, Figure 2 is an enlarged sectional view of a centrifugal separator, and Figure 3 is a displacer ( Fig. 4 is a graph showing the relationship between the number of times the polishing liquid is recycled and the polishing speed, and Fig. 5 is a graph showing the relationship between the number of times the polishing liquid is recycled and the polishing speed. A diameter distribution graph, FIG. 6 is a conceptual diagram of a conventional polishing apparatus, and FIG. 7 is a flowchart of the polishing process. 1... Polishing machine 3... Semiconductor wafer 5.
... Polishing cloth 6 ... Polishing liquid 7 ... Tank
8... Supply piping 9... Return piping 1
0... Supply pump 12... Centrifugal separator 16...
- Polishing stock solution 17a... Proportional valve 18... Stock solution tank 19... Solvent 20a... Proportional valve 21
... Solvent tank 22 ... Ultrasonic propagation velocity measuring device 23 ... Braking device 24 ... Displacer patent applicant Kyushu Electronic Metals Co., Ltd.
Claims (6)
対しコロイダルシリカを含有する研磨液を循環使用する
半導体ウェーハの研磨方法において、研磨液の循環径路
途中に遠心分離器を付設し、該遠心分離器により凝集粗
大シリカを除去しつつ研磨液を循環使用することを特徴
とする半導体ウェーハの研磨方法。(1) In a semiconductor wafer polishing method in which a polishing liquid containing colloidal silica is circulated to the polishing surface when polishing a semiconductor wafer with a polishing cloth, a centrifugal separator is attached in the middle of the polishing liquid circulation path. A method for polishing semiconductor wafers, characterized in that a polishing solution is circulated while removing aggregated coarse silica using a centrifugal separator.
を設けるべく前記研磨機とタンク間に付設された配管と
、該配管の途中部に付設された供給ポンプとを具備する
半導体ウェーハの研磨装置において、 前記タンクに遠心分離器を付設したことを特徴とする半
導体ウェーハの研磨装置。(2) A semiconductor wafer equipped with a polishing machine, a tank for storing polishing liquid, a pipe attached between the polishing machine and the tank to provide a circulation path, and a supply pump attached in the middle of the pipe. A polishing apparatus for semiconductor wafers, characterized in that a centrifugal separator is attached to the tank.
対しコロイダルシリカを含有する研磨液を循環使用する
半導体ウェーハの研磨方法において、研磨面に供給すべ
き研磨液の濃度を計測し、該計測値に基いて高濃度の研
磨原液及び水等溶媒を、適宜供給することにより研磨面
に供給すべき研磨液の濃度を一定に保持し、研磨布で半
導体ウェーハを研磨することを特徴とする半導体ウェー
ハの研磨方法。(3) When polishing a semiconductor wafer with a polishing cloth, in a semiconductor wafer polishing method that circulates a polishing liquid containing colloidal silica to the polishing surface, the concentration of the polishing liquid to be supplied to the polishing surface is measured, and the concentration of the polishing liquid to be supplied to the polishing surface is measured. A semiconductor wafer is polished with a polishing cloth while maintaining a constant concentration of a polishing liquid to be supplied to a polishing surface by appropriately supplying a high concentration polishing stock solution and a solvent such as water based on measured values. A method for polishing semiconductor wafers.
を設けるべく前記研磨機とタンク間に付設された配管と
、該配管の中途部に付設された供給ポンプとを具備する
半導体ウェーハの研磨装置において、 前記タンク内に超音波伝播速度計測器を配設する一方、
タンクに研磨液の原液タンク及び溶媒タンクを付設し、
これら両供給タンクに比例弁を取付け、更に超音波伝播
速度計測器の計測値を演算して前記比例弁を制御する制
動装置を備えさせたことを特徴とする半導体ウェーハの
研磨装置。(4) A semiconductor wafer comprising a polishing machine, a tank for storing polishing liquid, a pipe attached between the polishing machine and the tank to provide a circulation path, and a supply pump attached to the middle of the pipe. In the polishing apparatus, an ultrasonic propagation velocity measuring device is disposed in the tank, while
A polishing liquid stock solution tank and a solvent tank are attached to the tank.
A polishing apparatus for semiconductor wafers, characterized in that a proportional valve is attached to both of these supply tanks, and a braking device is further provided to control the proportional valve by calculating the measured value of an ultrasonic propagation velocity measuring device.
を設けるべく前記研磨機とタンク間に付設された配管と
、該配管の中途部に付設された供給ポンプとを具備する
半導体ウェーハの研磨装置において、 前記タンク内にディスプレーサを配設する一方、タンク
に研磨液の原液タンク及び溶媒タンクを付設し、これら
両タンクに比例弁を取付け、更にディスプレーサの受け
る浮力の計測値を演算して前記比例弁を制御する制動装
置を備えさせたことを特徴とする半導体ウェーハの研磨
装置。(5) A semiconductor wafer comprising a polishing machine, a tank for storing polishing liquid, a pipe attached between the polishing machine and the tank to provide a circulation path, and a supply pump attached to the middle of the pipe. In the polishing apparatus, a displacer is disposed in the tank, a polishing liquid stock tank and a solvent tank are attached to the tank, proportional valves are attached to both tanks, and the measured value of the buoyancy exerted on the displacer is calculated. 1. A polishing apparatus for semiconductor wafers, comprising a braking device for controlling said proportional valve.
対しコロイダルシリカを含有する研磨液を循環使用する
半導体ウェーハの研磨方法において、研磨面に供給すべ
き研磨液の濃度を計測し、該計測値に基いて高濃度の研
磨原液及び水等溶媒を、適宜供給することにより研磨面
に供給すべき研磨液の濃度を一定に保持し、更に、研磨
液の循環経路途中に遠心分離装置を付設し、該遠心分離
装置により凝集粗大シリカを除去しつつ研磨液を循環使
用して、研磨布で半導体ウェーハを研磨することを特徴
とする半導体ウェーハの研磨方法。(6) When polishing a semiconductor wafer with a polishing cloth, in a semiconductor wafer polishing method in which a polishing liquid containing colloidal silica is circulated to the polishing surface, the concentration of the polishing liquid to be supplied to the polishing surface is measured, and the concentration of the polishing liquid to be supplied to the polishing surface is measured. The concentration of the polishing liquid to be supplied to the polishing surface is maintained constant by appropriately supplying high-concentration polishing stock solution and solvent such as water based on the measured value, and a centrifugal separator is installed in the middle of the circulation path of the polishing liquid. 1. A method of polishing a semiconductor wafer, which comprises polishing the semiconductor wafer with a polishing cloth, which is attached to the centrifugal separator, while removing aggregated coarse silica and circulating a polishing liquid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1078977A JPH02257627A (en) | 1989-03-30 | 1989-03-30 | Method and apparatus for polishing of semiconductor wafer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1078977A JPH02257627A (en) | 1989-03-30 | 1989-03-30 | Method and apparatus for polishing of semiconductor wafer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02257627A true JPH02257627A (en) | 1990-10-18 |
Family
ID=13676955
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1078977A Pending JPH02257627A (en) | 1989-03-30 | 1989-03-30 | Method and apparatus for polishing of semiconductor wafer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02257627A (en) |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0798080A1 (en) * | 1996-03-27 | 1997-10-01 | Shin-Etsu Handotai Company Limited | Lapping apparatus and method |
| EP0822033A1 (en) * | 1996-07-29 | 1998-02-04 | Integrated Process Equipment Corp. | Slurry recycling in chemical-mechanical polishing (CMP) apparatus |
| US6183352B1 (en) | 1998-08-28 | 2001-02-06 | Nec Corporation | Slurry recycling apparatus and slurry recycling method for chemical-mechanical polishing technique |
| KR20020003704A (en) * | 2000-06-27 | 2002-01-15 | 장정훈 | Module for regenerating slurry of chemical mechanical polishing apparatus |
| JP2002016030A (en) * | 2000-06-27 | 2002-01-18 | Mitsubishi Chemical Engineering Corp | Preparation method and apparatus of polishing liquid |
| JP2002016029A (en) * | 2000-06-27 | 2002-01-18 | Mitsubishi Chemical Engineering Corp | Preparation method and apparatus for polishing liquid |
| JP2002327170A (en) * | 2001-04-27 | 2002-11-15 | Kao Corp | Polishing liquid composition |
| JP2003170034A (en) * | 2001-12-05 | 2003-06-17 | Fujitsu Ltd | Chemical liquid-feeding apparatus and slurry preparation method |
| KR100393007B1 (en) * | 2001-07-09 | 2003-07-31 | (주)풍남반도체테크 | Regenerating process and regenerating system to regenerate waste slurry from semiconductor wafer manufacturing process |
| JP2003257906A (en) * | 2002-03-05 | 2003-09-12 | Sumitomo Mitsubishi Silicon Corp | Method for polishing semiconductor wafer |
| WO2008093450A1 (en) * | 2007-01-31 | 2008-08-07 | Nitta Haas Incorporated | Additive for abrasive composition |
| WO2012030005A1 (en) * | 2010-09-02 | 2012-03-08 | 씨앤지하이테크 주식회사 | Device for supplying slurry for semiconductor, provided with pipe clogging prevention means |
-
1989
- 1989-03-30 JP JP1078977A patent/JPH02257627A/en active Pending
Cited By (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0798080A1 (en) * | 1996-03-27 | 1997-10-01 | Shin-Etsu Handotai Company Limited | Lapping apparatus and method |
| US5800251A (en) * | 1996-03-27 | 1998-09-01 | Shin-Etsu Handotai Co., Ltd. | Apparatus and method of lapping works |
| EP0822033A1 (en) * | 1996-07-29 | 1998-02-04 | Integrated Process Equipment Corp. | Slurry recycling in chemical-mechanical polishing (CMP) apparatus |
| US6183352B1 (en) | 1998-08-28 | 2001-02-06 | Nec Corporation | Slurry recycling apparatus and slurry recycling method for chemical-mechanical polishing technique |
| GB2344780B (en) * | 1998-08-28 | 2003-05-07 | Nec Corp | Slurry recycling apparatus and slurry recycling method for chemical-mechanical polishing technique |
| KR20020003704A (en) * | 2000-06-27 | 2002-01-15 | 장정훈 | Module for regenerating slurry of chemical mechanical polishing apparatus |
| JP2002016030A (en) * | 2000-06-27 | 2002-01-18 | Mitsubishi Chemical Engineering Corp | Preparation method and apparatus of polishing liquid |
| JP2002016029A (en) * | 2000-06-27 | 2002-01-18 | Mitsubishi Chemical Engineering Corp | Preparation method and apparatus for polishing liquid |
| JP2002327170A (en) * | 2001-04-27 | 2002-11-15 | Kao Corp | Polishing liquid composition |
| KR100393007B1 (en) * | 2001-07-09 | 2003-07-31 | (주)풍남반도체테크 | Regenerating process and regenerating system to regenerate waste slurry from semiconductor wafer manufacturing process |
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| JP2003257906A (en) * | 2002-03-05 | 2003-09-12 | Sumitomo Mitsubishi Silicon Corp | Method for polishing semiconductor wafer |
| WO2008093450A1 (en) * | 2007-01-31 | 2008-08-07 | Nitta Haas Incorporated | Additive for abrasive composition |
| JP2008192656A (en) * | 2007-01-31 | 2008-08-21 | Nitta Haas Inc | Additive for polishing constituent |
| US8308972B2 (en) | 2007-01-31 | 2012-11-13 | Nitta Haas Incorporated | Additive for polishing composition |
| US8420539B2 (en) | 2007-01-31 | 2013-04-16 | Nitta Haas Incorporated | Additive for polishing composition |
| WO2012030005A1 (en) * | 2010-09-02 | 2012-03-08 | 씨앤지하이테크 주식회사 | Device for supplying slurry for semiconductor, provided with pipe clogging prevention means |
| KR101138403B1 (en) * | 2010-09-02 | 2012-04-26 | 씨앤지하이테크 주식회사 | Apparatus for supplying slurry for semiconductor having means for preventing clogging pipe |
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