JPS63222433A - Freeze vacuum drying method - Google Patents

Abstract

PURPOSE:To reduce contamination and drying irregularities of a body to a large extent, by freezing water droplets in drying the body, which is not yet dry, and sublimating the ice in a vacuum. CONSTITUTION:A wafer 2 immediately after washing is put in a freezing chamber 1. When a valve 10 is opened, low temperature nitrogen gas is blown through a nitrogen-gas diffusion pipe 4, and water droplets on the wafer 2 are instantly frozen. The valve 10 is closed, and a partitioning door 7 to a vacuum chamber 5 is opened. Because of sudden reduction in pressure, ice component is sublimated (a), and contaminated material is also drawn in a vacuum. Since a valve 9 is opened intactly, the contaminated material and the water droplets are sucked with a vacuum pump, and the wafer 2 is completely dried without contamination again. The valve 9 is closed and nitrogen gas at normal temperature is blown through a nitrogen pipe 8. Thus the freezing chamber 1 and the vacuum chamber 5 are returned to the normal temperature. In this way, the contamination and irregularities of dryness of the wafer 2 are largely decreased.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、半導体プロセスにおいて必要とされる高清
浄物体の凍結乾燥法、特に汚染を鏝小眼に防ぐ凍結乾燥
法に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a freeze-drying method for highly clean objects required in semiconductor processes, and in particular to a freeze-drying method for preventing contamination from occurring.

〔従来の技術〕[Conventional technology]

従来、半導体プロセスで行なわれているクエハ乾燥法は
スピンドライヤーを用いた乾燥法である。スピンドライ
ヤーの断面図を第６図に示す。図においてＨはフェノ１
を入れるターンテーブル、　Ｑｌは駆動モータ、Ｑｌは
この駆動モータにより回転される回転軸、ＱｆＨ−ｊタ
ーンテーブルを包囲し、水受けの作用をするチャンバー
、１ηは排水口である。The quefer drying method conventionally used in semiconductor processes is a drying method using a spin dryer. A cross-sectional view of the spin dryer is shown in FIG. In the diagram, H is pheno 1
Ql is a drive motor, Ql is a rotating shaft rotated by this drive motor, QfH-j is a chamber that surrounds the turntable and acts as a water receptacle, and 1η is a drain port.

従来のクエハ乾燥は上記の装置を用い、九とえば洗浄後
のクエハをターンテーブルθ埼に入れた後、乾空雰囲気
でターンテーブルを高速回転させることにより、遠心力
によりクエハと水滴を分離し、クエハが乾燥するように
なっている。Conventional drying of water droplets uses the above-mentioned equipment.For example, after washing the water droplets is placed on a turntable θ, the turntable is rotated at high speed in a dry air atmosphere to separate the water droplets from the water droplets using centrifugal force. , Queja is supposed to be dry.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

上記のように遠心力を用いて乾燥する方法では方向性が
あるため、後に記すようにパターン段差部分の水分残留
や、水滴に汚染物混入時の遠心方向への汚染の拡散、高
速回転による装置内発塵、また、除々に乾燥するための
乾燥ムラしかるに第７〜９図は従来乾燥法により乾燥す
る図面である。As mentioned above, the drying method using centrifugal force is directional, so as described later, moisture may remain in the step part of the pattern, contamination may spread in the centrifugal direction when contaminants are mixed in with water droplets, and the high-speed rotation of the device Internal dust generation and uneven drying due to gradual drying. However, FIGS. 7 to 9 are diagrams showing drying by the conventional drying method.

第７図は乾燥前で段差部および゛平担部に汚染含有水分
がある。第８図は乾燥途中で水分が減少したため、汚染
物濃度が高くなる。汚染物は水滴内を自由に幼く丸め、
クエハに付着するものもある。第９図は乾・燥終了後で
、遠心力が右方向に働いたため段差部に水分残留。平担
部に汚染物が残さとして残る。In FIG. 7, before drying, there is moisture containing contamination in the step portion and the flat portion. In FIG. 8, the contaminant concentration increases because the water content decreases during drying. Contaminants freely roll up inside water droplets,
Some also attach to Kueha. Figure 9 shows that after the drying process was completed, moisture remained in the stepped area due to centrifugal force acting in the right direction. Contaminants remain on the flat surface.

この発明は、かかる問題点を解決するためになされたも
ので、被乾燥物の最小汚染による完全乾燥を目的とする
。This invention was made to solve this problem, and aims to completely dry the material to be dried with minimal contamination.

〔問題点を解決する丸めの手段〕[Rounding method to solve problems]

この発明に係る凍結真空乾燥法は、被乾燥物上の水分を
瞬時凍結し、真空内で昇華させる方法である。The freeze-vacuum drying method according to the present invention is a method in which moisture on an object to be dried is instantly frozen and sublimated in a vacuum.

〔作用〕[Effect]

この発明においては、水分を凍結するため、汚染物が被
洗浄物に沈着せず氷と共に昇華し、〔実施例〕 第１図はこの発明の一実施例を示す断面図である。この
図におＡで１１１は冷凍室、＋２１は被乾燥物であるク
エハ、１Ｂ＋は液体窒素源、＋４１ｒｉ冷凍室１！１内
に窒素ガスを噴き出す散気管、＋１１１は真空室、（６
）は真空ポンプ、（７）は冷凍室１１１と真空室＋５１
１＆−Ｌきるしきり扉、（８）ハ窒素管、（９）と１０
１　ｉパルプである。In this invention, since water is frozen, contaminants do not settle on the object to be cleaned, but sublimate together with the ice. [Embodiment] FIG. 1 is a sectional view showing an embodiment of the invention. In this figure, in A, 111 is the freezing chamber, +21 is the material to be dried, 1B+ is the liquid nitrogen source, +41ri is the diffuser pipe that blows out nitrogen gas into the freezing chamber 1!
) is the vacuum pump, (7) is the freezer compartment 111 and vacuum chamber +51
1&-L closing door, (8) C nitrogen pipe, (9) and 10
1 i pulp.

洗浄直後のクエハを冷凍室１１）に入れる。第２図はこ
の時のクエハ上の水滴の状態で、汚染物は自由に幼くの
で時間がたてばクエハに沈着する可能性がある。パルプ
＋１０１　ｉ開けると窒素ガス散気管から低温窒素ガス
がふき出し、クエハ上の水滴は瞬時に凍結する。第８図
は凍結状態で水滴が凍結したため汚染物は動きを封じら
れている。パルプ＋１０１を閉めあらかじめ真空に引い
である真空室（６１とのしきり扉（７）を開ける。急激
な減圧のため水分は昇化し、汚染物も共に真空に引かれ
る。第４図は部分的に昇華したところである。Immediately after washing, put the kuehaya into the freezer compartment 11). Figure 2 shows the state of the water droplets on the quefer at this time, and since the contaminants are young and free, there is a possibility that they will settle on the quefer over time. Pulp+101 i When opened, low-temperature nitrogen gas blows out from the nitrogen gas diffuser pipe, and the water droplets on the quefer freeze instantly. Figure 8 shows a frozen state in which the movement of contaminants is blocked because the water droplets are frozen. Close the pulp + 101 and open the door (7) between the vacuum chamber (61), which is previously evacuated. Due to the sudden pressure reduction, the moisture rises and the contaminants are also evacuated. Figure 4 shows a partial It has just been sublimated.

この時、パルプ（９１ｔＩ″ｉ開いたま１なので、汚染
物や水滴は真空ポンプに引かれ、クエハは再汚染もなく
完全に乾燥する。At this time, since the pulp (91tI''i) remains open, contaminants and water droplets are drawn by the vacuum pump, and the pulp is completely dried without re-contamination.

第５図はＩＩＬ燥後のクエハである。この後、パルプ（
９）ヲ閉め窒素管（８）から常温窒素ガスを出すことに
より、冷凍室＋１１および真空室＋５１は常温にもどり
、！１図の装置を用いた凍結乾燥工程を終了する。FIG. 5 shows the queja after IIL drying. After this, pulp (
9) By closing the door and releasing room temperature nitrogen gas from the nitrogen pipe (8), the freezer compartment +11 and vacuum room +51 return to room temperature! The freeze-drying process using the apparatus shown in Figure 1 is completed.

なお、上記実施列では冷凍室ｌ；と真空室（５）？並べ
たが第１０％第１１図の装置でも類似の効果が期待でき
る。In addition, in the above implementation row, the freezing chamber l; and the vacuum chamber (5)? A similar effect can be expected with the device shown in FIG. 11 at 10%.

第１０図は冷凍室を真空室でおおったものである。第１
図より、より瞬間的な真空化が可能となる。第１１図は
冷凍室と真空室？一つにしたもので、真空ポンプの強さ
により昇化速度を調節できる。また、装置の構成に応じ
て窒素ガスのかわりに他の低温媒体、電気冷凍機、電子
冷却機など金柑いることができる。クエハ洸浄装置と組
み合わせて１つの装置にすることもできる０ この発明はセラミック、ガラスなどの材料。Figure 10 shows a freezer compartment covered with a vacuum chamber. 1st
From the figure, more instantaneous vacuuming is possible. Is Figure 11 a freezing chamber and a vacuum chamber? With a single unit, the rate of elevation can be adjusted depending on the strength of the vacuum pump. Also, depending on the configuration of the device, other low-temperature media such as electric refrigerators, electronic coolers, etc. can be used instead of nitrogen gas. It can also be combined with the Queha Cleaning Device into a single device.0 This invention can be applied to materials such as ceramics and glass.

マスク、カセット、ビンセットなどの冶工Ａ％無塵化、
など高清浄度を要するすべての物体の真空乾燥に用いる
ことができる。A% dust-free jig work for masks, cassettes, bottle sets, etc.
It can be used for vacuum drying of all objects that require high cleanliness.

ところで、上記説明では水分乾燥について述べたが他の
液体の乾燥にも利用できることは言うまでもない。Incidentally, although the above description has been made regarding moisture drying, it goes without saying that it can also be used for drying other liquids.

〔発明の効果〕〔Effect of the invention〕

この発明は以上説明した通り、非乾燥物体乾燥において
水滴を凍結し、真空内昇華することにより物体の汚染お
よび乾燥むらを大幅に減少する効果がある。As explained above, the present invention has the effect of significantly reducing contamination and uneven drying of objects by freezing water droplets and sublimating them in a vacuum when drying non-dry objects.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図はこの発明の一実施例を示す断面図、第２〜５図
はこの発明を説明する模式断面図、第６図は従来のスピ
ンドライヤーを示す断面図、第７〜９図は従来法を説明
する模式断面図、第１０図、第１１図はこの発明の他の
実施例に用いられる装置の断面図である。 図において１１１は工程において真空にもなる凍結−、
ｔｅｌは被乾燥物体、（４１は窒素ガス散気管、（６）
は真空室、αｐは水滴、（１２１は汚染物、（＋３はタ
ーンテーブル、　Ｑ４は窒素ガス管、（至）は冷凍室兼
真空室である。 なお、各図中同一符号は同一または相当部分を示す。Fig. 1 is a sectional view showing an embodiment of the present invention, Figs. 2 to 5 are schematic sectional views illustrating the invention, Fig. 6 is a sectional view showing a conventional spin dryer, and Figs. 7 to 9 are conventional FIGS. 10 and 11 are schematic cross-sectional views for explaining the method, and are cross-sectional views of devices used in other embodiments of the present invention. In the figure, 111 is frozen which also becomes a vacuum during the process.
tel is the object to be dried, (41 is the nitrogen gas diffuser pipe, (6)
is a vacuum chamber, αp is a water droplet, (121 is a contaminant, (+3 is a turntable, Q4 is a nitrogen gas pipe, and (to) is a freezer and vacuum chamber. In each figure, the same reference numerals indicate the same or equivalent parts. shows.

Claims (1)

【特許請求の範囲】[Claims] （１）被乾燥物体に付着した液滴を瞬間冷凍した後、真
空内で昇華させる凍結真空乾燥法。(1) A freeze-vacuum drying method in which droplets attached to an object to be dried are flash-frozen and then sublimated in a vacuum.