1305012 九、發明說明： 【發明戶斤屬之技術領域3 發明領域 本發明係有關於一種例如用以對業已進行洗淨處理之 5 基板進行乾燥處理之乾燥處理裝置及乾燥處理方法。 【先前技術】 發明背景 液晶顯示裝置或半導體裝置之製造步驟中，有一於半 導體晶圓或玻璃基板等之基板上形成電路圖之步驟。形成 10 電路圖時，於業已成膜之基板塗布光阻，然後曝光，並在 曝光後藉顯像液進行顯像處理，然後以蝕刻液進行蝕刻處 理。藉此，於基板之表面精密地形成電路圖。 若於基板形成電路圖，可藉剝離液氣去除附著殘留於 其基板表面之光阻膜或光阻殘渣等有機物。若藉剝離液除 15 去有機物，則以洗淨液洗淨處理其基板板面，接著交接到 下一步驟。 由於業經洗淨處理之基板充滿洗淨液，因此必須在交 接到下一步驟前進行乾燥處理。對基板進行乾燥處理時， 係將前述基板收容於室内，並將氮氣等製程氣體供給於該 20 室内，然後利用加熱器加熱進行乾燥處理。 然而，如此對基板進行乾燥處理時，由於室内為大氣 壓力，因此會提高加熱溫度，且若沒有加長加熱時間，則 無法確實地對基板進行乾燥處理。 此時，當提高加熱溫度時，則要求乾燥處理裝置的耐 ^05012 熱性，且因為形成於基板之電路或膜等的種類而加熱溫度 會受到限制，無法完全提高加熱溫度。當加長加熱時間時， 由於光是此一處理就花費多時，因此生產性降低。 因此’最近不僅使用加熱器對供給到室内之基板加 5熱，還使該室内減壓並使基板乾燥。藉在業已減壓之室内 進行基板之乾燥處理，即使基板的加熱溫度較低，也具有 可在短時間内使前述基板確實乾燥的優點。在減壓環境氣 • 體下對基板進行乾燥處理之習知技術已揭示專利文獻1。 專利文獻1所揭示之裝置具有室，並且於該室内設有對 10基板加熱之加熱板。用以使該内部減壓之真空果係與前述 室内連接，，並且在基板之乾燥處理後，可供給用以使室 内恢復到大氣壓力之清洗用氣體。又，也揭示有在減壓狀 態下，於室内經常清洗氣體，並且作為用以排出該室内之 水蒸氣之載體氣體。 15【專利文獻1】日本專利公開公報特開平第2-65233號 【發明内容】 發明概要 根據專利文獻1_示4知技術，基板之乾燥處理開 始時’可使衫泵作動以減少室内的壓力，並且當使真空 泵作動之狀態下開放開_等而開始減壓時，在其開始時 會急速地排出室内的氣體。 當急速排出室内之氣體時’由於室1内容易產生|L流， 因此沉殿於室内之微粒會因為該亂流而散亂，並且附著於 20 1305012 室之内壁的微粒會剝離且飛散。結果，該等微粒會附著於 基板，成為基板之污染原因。 本發明係提供一種基板之乾燥處理裝置及乾燥處理方 法，可在使室内減壓且對基板進行乾燥處理時，室内難以 5 產生亂流，藉此殘留於室内之微粒不會飛散且附著於基板 上。 本發明係一種在減壓環境下對基板進行乾燥處理之乾 燥處理裝置，包含：室，係前述基板可供給到其内部者； 加熱機構，係對供給到前述室内之基板進行加熱者；減壓 10 機構，係對前述室内進行減壓者；氣體供給機構，係將製 程氣體供給到前述室内者；及控制裝置，係控制前述減壓 機構，對前述室内進行減壓，並且控制前述氣體供給機構， 在減壓開始前將前述製程氣體供給到前述室内，並在減壓 開始後慢慢減少供給量，使前述室内減壓者。 15 本發明係一種在減壓環境氣體下對基板進行乾燥處理 之乾燥處理方法，包含：供給步驟，係將前述基板供給到 室内者；加熱步驟，係加熱供給到前述室内之前述基板者； 減壓步驟，係預先供給製程氣體到前述室内，然後使該室 内減壓者；及減少製程氣體流量步驟，係在前述室内開始 20 減壓至降低到預定之壓力的期間，慢慢減少供給到前述室 内之製程氣體之流量者。 根據本發明，係先將製程氣體供給到室内後開始減 壓，並且在開始減壓後慢慢減少製程氣體之供給量。因此， 由於可防止在減壓開始時室内之氣體的流動或壓力急速產 1305012 I：實施令 生變動，因此·5]~ 防止殘留於室 式】 内之微粒飛散而附著於基板。 較佳實施例之詳細說明 5BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drying treatment apparatus and a drying treatment method, for example, for drying a substrate which has been subjected to a cleaning treatment. [Prior Art] In the manufacturing steps of a liquid crystal display device or a semiconductor device, there is a step of forming a circuit pattern on a substrate such as a semiconductor wafer or a glass substrate. When the circuit pattern is formed, the photoresist is coated on the substrate which has been formed, and then exposed, and after exposure, the development liquid is applied by the developing liquid, and then etched by the etching liquid. Thereby, a circuit pattern is precisely formed on the surface of the substrate. When a circuit pattern is formed on the substrate, the organic material such as the photoresist film or the photoresist residue adhering to the surface of the substrate can be removed by the stripping liquid gas. If the organic matter is removed by the stripping solution, the substrate surface is washed with a washing solution, and then transferred to the next step. Since the washed substrate is filled with the cleaning liquid, it must be dried before being delivered to the next step. When the substrate is subjected to a drying treatment, the substrate is housed in a chamber, and a process gas such as nitrogen is supplied to the chamber 20, and then heated by a heater to perform a drying treatment. However, when the substrate is dried in this manner, since the room is at atmospheric pressure, the heating temperature is increased, and if the heating time is not lengthened, the substrate cannot be surely dried. At this time, when the heating temperature is raised, the heat resistance of the drying treatment apparatus is required to be 05012, and the heating temperature is limited by the type of the circuit or the film formed on the substrate, and the heating temperature cannot be completely increased. When the heating time is lengthened, since it takes a lot of time for the light to be treated, the productivity is lowered. Therefore, recently, not only the heater is used to add heat to the substrate supplied to the room, but also the chamber is depressurized and the substrate is dried. By drying the substrate in a room where the pressure has been reduced, even if the heating temperature of the substrate is low, there is an advantage that the substrate can be surely dried in a short time. Patent Document 1 discloses a conventional technique for drying a substrate under a reduced pressure atmosphere. The apparatus disclosed in Patent Document 1 has a chamber, and a heating plate for heating the substrate 10 is provided in the chamber. The vacuum system for decompressing the inside is connected to the chamber, and after the substrate is dried, a cleaning gas for returning the chamber to atmospheric pressure can be supplied. Further, it has been revealed that the gas is often cleaned indoors under reduced pressure and serves as a carrier gas for discharging water vapor in the chamber. [Patent Document 1] Japanese Laid-Open Patent Publication No. Hei No. 2-65233. SUMMARY OF THE INVENTION SUMMARY OF THE INVENTION According to Patent Document 1 to 4, when the drying process of the substrate is started, the shirt pump can be actuated to reduce the pressure in the room. When the vacuum pump is actuated and the pressure is reduced, the gas in the room is rapidly discharged at the beginning of the vacuum pump. When the gas in the chamber is rapidly discharged, the |L flow is likely to occur in the chamber 1, so that the particles in the chamber are scattered due to the turbulent flow, and the particles adhering to the inner wall of the 201305012 chamber are peeled off and scattered. As a result, the particles adhere to the substrate and cause contamination of the substrate. The present invention provides a substrate drying processing apparatus and a drying processing method, which are capable of causing turbulence in a room when the chamber is depressurized and dried, thereby preventing particles scattered in the chamber from scattering and adhering to the substrate. on. The present invention relates to a drying treatment apparatus for drying a substrate in a reduced pressure environment, comprising: a chamber to which the substrate can be supplied; and a heating mechanism for heating a substrate supplied to the chamber; a mechanism for decompressing the indoor chamber; a gas supply mechanism for supplying a process gas to the indoor unit; and a control device for controlling the pressure reducing mechanism to decompress the chamber and controlling the gas supply mechanism The process gas is supplied to the inside of the room before the start of the pressure reduction, and the amount of supply is gradually decreased after the start of the pressure reduction, and the room is decompressed. The present invention is a drying treatment method for drying a substrate under a reduced-pressure ambient gas, comprising: a supply step of supplying the substrate to a room; and a heating step of heating the substrate to the substrate; The pressing step is a step of supplying the process gas to the chamber in advance, and then decompressing the chamber; and reducing the process gas flow rate, and gradually reducing the supply to the aforementioned period when the indoor pressure is reduced to a predetermined pressure. The flow of process gas in the room. According to the present invention, the process gas is first supplied to the room to start decompression, and the amount of process gas is gradually reduced after the start of depressurization. Therefore, it is possible to prevent the flow of gas or the pressure in the room at the start of decompression from being rapidly produced. 1305012 I: The operation fluctuates, so that the particles remaining in the chamber are prevented from scattering and adhering to the substrate. Detailed Description of the Preferred Embodiments 5
10 以下，參照圖式說明本發明之一實施型態。 二第圖糸‘,、員不基板之處理裝置卜該處理裝置1具有盒站 2忒益站2具有：將未處理之基板W收容於盒3之裂载部4、 及如後所述將業經洗淨及乾燥處理之基板w回收於 卸載部5。 、现< 交接單元7係鄰接設置於前述盒站2。旋轉洗淨處理單 元8與乾烯處理單元9係鄰接設置於該交接單元7。 前述交接單元7設有朝X、Υ及Θ方向驅動之機器 11。該機器人11具有可分別處理處理前之基板冒與處理後 之基板W之一對臂12，藉其中一臂12取出收容於前述裝栽 部4之盒3之未處理基板W後供給於前述旋轉洗淨處理單_ 15 供給於旋轉洗淨處理單元8之基板W係在此進行洗、事 處理。業經洗淨處理之基板w可藉前述機器人η之 — 12而取出’並且供給到鄰接设置於s亥旋轉洗淨處理單元$之 前述乾燥處理單元9。基板W則藉該乾燥處理單元9進行如 20 後述之乾燥處理。 在前述乾燥處理單元9業經乾燥處理之基板w由前述 機器人11之另一臂12取出然後收納於前述盒站2之卸載部5 之盒3。 前述乾燥處理單元9係如第2圖所示具有室15。該室15 1305012 内設有用以載置基板W之檯16。該檯16設有作為加熱機構 之加熱器17，並且該加熱器17係由加熱器控制器18來控制 通電。又，雖然沒有圖示，但前述室15設有用以使前述基 板W出入之出入口。該出入口係藉閘（未圖示）來開關。 5 由加熱裔17加熱之基板W的溫度係由溫度檢測19檢 測。該溫度檢測器19之檢測信號輸入於控制裝置21。控制 裝置21根據設定溫度而控制前述加熱器控制器18，並且將 基板W之溫度維持在設定溫度。 前述室15係與排氣管23之一端連接。該排氣管23之另 10 一端係與排氣泵24連接。藉此，室15内可藉前述排氣泵24 減壓。 前述排氣管2 3之中途部設有用以控制開關之開關控制 閥25及排氣流量調整閥26，且該排氣流量調整閥26係當開 關控制閥25打開時，可調整前述排氣泵24在室内之單位時 15 間内的排氣量、也就是室15内之減壓速度。 由前述排氣泵24減壓之前述室15内之壓力可由壓力檢 測器28檢測。該壓力檢測器28之檢測信號輸入前述控制裝 置21，並根據該輸入來控制前述開關控制閥25之開關、及 前述排氣流量調整閥26之開度。 20 前述室15與用以供給氮氣等之製程氣體之氣體供給管 31連接。該氣體供給管31設有用以控制前述製程氣體之供 給量之供氣流量控制閥32及開關閥33。 前述氣體供給管31之前端係朝室15内突出，並於此與 氣體供給喷嘴34連接。詳細部分雖未圖示，但前述氣體供 1305012 給噴嘴34係中空的圓盤狀，且有複數之噴嘴孔開口形成於 其板面。藉此，可將製程氣體均一地供給到前述室15内。 其次，說明藉前述構成之乾燥處理單元9對業經洗淨處 理之基板W進行乾燥處理時之作用。 5 第3圖係顯示基板W對室15之供給、開關控制閥25之開 關、排氣泵24之作動及製程氣體之供給之時間圖。第4圖之 圖表A係排氣泵24所排氣之室15内之每單位時間之排氣量 φ 與時間之關係，圖表B係顯示供氣流量控制閥3 2控制之製程 氣體之供給量與時間之間的關係。 10 在時間T1基板W係供給於室15内，但由其之前的時間 T0係供給製程氣體。又，排氣泵24雖然有作動，但由於開 關控制閥25關閉，因此排氣泵24進行之排氣不會作用於室 15内。也就是說，室15内沒有減壓。 當在時間T1基板W供給到室15時，開關控制閥25會開 15 放，並且排氣流量調整閥26由預定之開度控制為漸漸加 φ 大，使每單位時間之排氣量增加，並且控制供氣流量控制 閥32，使供給到室15内之製程氣體的供給量漸漸減少。 在時間T1基板W供給到室15内之同時，開始對加熱器 17的通電，並且室15内係加熱到設定溫度。又，加熱器17 20 進行之加熱亦可在基板W供給到室15之前進行。 在前述開關控制閥25開放且室15内之減壓開始之時間 T1，供給到該室15内之製程氣體在每單位時間的供給量會 到達Q1，藉此，室15内的壓力也會上昇到高於大氣壓力之 壓:力。 10 1305012 又，至15内之壓力係由壓力檢測器28檢測。而當室15 内的壓力成為預先設定之壓力時，會控制製程氣體的供 給，使至15内之壓力不會再上昇。 在將基板W供給到室15之時間们開放開關控制閥25且 5開始室15内的減壓時’減廢開始時，室⑽之氣體會急速 排出。然而，製程氣體會供給到室15内，直到成為由壓力 感測|§28所没定之壓力為止。因此，減壓開始時，即使由 φ 冑15内急速排出製程氣體’室15内之壓力止會稍微降低， 但不會大幅降低。 10 藉此，在減壓開始時之開關控制閥25開放時，室15内 之壓力不會急速變動而產生亂流，因此可防止沉澱於室15 内且附著於内面之微粒會散亂於室15内且附著於基板w。 供給於室15之製程氣體的供給量係如第4圖之圖表3所 示，由室15内之減壓開始之時間丁丨慢慢減少，並且在經過 15預定時間之時間T2時，每單位時間之供給量為Q2。 修另一方面，排氣泵24每單位時間之排氣量如圖表入所 示，由時間τι漸漸增加，並在時間Τ2之時間點到達νι。此 時之排氣速度可藉排氣流量調整閥26之開度調整而控制。 如此，藉漸漸減少製程氣體供給到室15内之供給量， 2〇並漸漸增加室15内之排氣量，在時間T2室15内之壓力會降 低到預疋之壓力，也就是適合對基板W進行乾燥處理之壓 力。 由時間T2到時間T3 ’會持續因應於排氣流量調整間^ 之開度之每單位時間之減量¥1及供氣流量控㈣32在製 1305012 程氣體之每單位時間的供給量Q2。藉此，由於室15内維持 在預定之減壓壓力，因此基板W可在其減壓壓力下進行乾 燥處理。 對基板W進行乾燥處理期間，製程氣體之供給係以每 5 單位時間Q2之供給量來進行，排氣係以作為與供給量Q2平 衡之量之VI的排氣量。因此，乾燥處理時，由基板W產生 之水蒸氣係藉排氣量VI所排氣之製程氣體而由室15内排 φ 出，因此可促進乾燥處理。又，其間，由於室15内之壓力 沒有變動，因此室15内也不會有產生亂流而有微粒附著於 10 基板W的情況。 如此，當基板W之乾燥處理結束時，時間T3到時間T4 中，排氣流量調整閥26會漸漸關閉，並且在時間T4關閉開 關控制閥25。藉此，排氣泵24進行室15内每單位時間之排 氣會由VI漸漸減少為0。另一方面，製程氣體之供給量會由 15 Q2漸漸增加，並且在時間T4為Q1。而且，室1内的壓力會 φ 成為大氣壓力，當此情況在時間T5被壓力檢測器28檢測出 時，製程氣體之供給量會為〇。 如此，當前述室15内之壓力回到大氣壓力時，室15内 之每單位時間的排氣量會漸漸減少，並且漸漸增加製程氣 20 體每單位時間之供給量。 因此，當室15回到大氣壓力時，由於室15内之壓力不 會急速上昇，因此此時亦可防止殘留於室15内之微粒飛散 而附著於基板W。 又，前述一實施型態中，係在由室内之減壓開始時或 12 1305012 減壓狀態回到大氣壓力時，使排氣泵在作動之下，開關控 制閥進行開關控制，但亦可不設有開關控制閥而控制排氣 泵之發停。 5 【圖式簡單說明】 第1圖係顯示本發明之一實施型態之基板處理裝置之 概略說明圖。 φ 第2圖係用以對基板進行乾燥處理之乾燥處理單元。 第3圖係用以說明設置於乾燥處理單元之各種機器之 10 動作之時間表。 第4圖係顯示每單位時間之室内的排氣量與製程氣體 之供給量之關係之圖表。 13 1305012 【主要元件符號說明】 1...基板之處理裝置 18...加熱器控制器 2…盒站 19...溫度感測器 - 3…盒 21...控制裝置 — 4...裝載部 23...排氣管 ' 5".卸載部 24...排氣泵 • 7.··交接單元 25...開關控制閥 8...旋轉洗淨處理單元 26...排氣流量調整閥 9...乾燥處理單元 28...壓力檢測器 11...機器 31...氣體供給管 12...機器臂 32...供氣流量控制閥 15···室 33...開關閥 16…檯 34…氣體供給喷嘴 • 17...加熱器 W.··絲 1410 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The processing device 1 has a box station 2, and the station 2 has an unprocessed substrate W housed in the cracked portion 4 of the cartridge 3, and will be described later. The substrate w which has been washed and dried is recovered in the unloading unit 5. The present < delivery unit 7 is adjacently disposed in the cassette station 2 described above. The spin cleaning unit 8 is disposed adjacent to the dry olefin processing unit 9 in the delivery unit 7. The aforementioned transfer unit 7 is provided with a machine 11 that is driven in the X, Υ and Θ directions. The robot 11 has a pair of arms 12 that can handle the substrate before the processing and the processed substrate W, and the arm 12 is taken out from the unprocessed substrate W of the cartridge 3 accommodated in the loading unit 4, and then supplied to the rotation. Washing Process Sheet _ 15 The substrate W supplied to the spin cleaning processing unit 8 is subjected to washing and processing. The substrate w which has been subjected to the cleaning treatment can be taken out by the aforementioned robot η -12 and supplied to the above-described drying processing unit 9 which is disposed adjacent to the s-spinning cleaning processing unit $. The substrate W is subjected to a drying process as will be described later by the drying processing unit 9. The substrate w which has been dried by the drying processing unit 9 is taken out by the other arm 12 of the robot 11 and then stored in the cassette 3 of the unloading portion 5 of the cassette station 2. The drying processing unit 9 has a chamber 15 as shown in Fig. 2 . A stage 16 for placing the substrate W is disposed in the chamber 15 1305012. The stage 16 is provided with a heater 17 as a heating means, and the heater 17 is controlled by the heater controller 18 for energization. Further, although not shown, the chamber 15 is provided with an entrance and exit for allowing the substrate W to enter and exit. The entrance and exit are switched by a brake (not shown). 5 The temperature of the substrate W heated by the heating element 17 is detected by the temperature detection 19. The detection signal of the temperature detector 19 is input to the control device 21. The control device 21 controls the heater controller 18 in accordance with the set temperature and maintains the temperature of the substrate W at the set temperature. The chamber 15 is connected to one end of the exhaust pipe 23. The other end of the exhaust pipe 23 is connected to the exhaust pump 24. Thereby, the chamber 15 can be decompressed by the exhaust pump 24. The switch control valve 25 and the exhaust flow rate adjustment valve 26 for controlling the switch are provided in the middle of the exhaust pipe 23, and the exhaust flow rate adjustment valve 26 can adjust the exhaust pump when the switch control valve 25 is opened. 24 The amount of exhaust in 15 indoor units, that is, the decompression speed in chamber 15. The pressure in the chamber 15 decompressed by the exhaust pump 24 described above can be detected by the pressure detector 28. The detection signal of the pressure detector 28 is input to the control means 21, and the opening of the switch control valve 25 and the opening degree of the exhaust gas flow rate adjusting valve 26 are controlled based on the input. The chamber 15 is connected to a gas supply pipe 31 for supplying a process gas such as nitrogen gas. The gas supply pipe 31 is provided with an air supply flow rate control valve 32 and an on-off valve 33 for controlling the supply amount of the process gas. The front end of the gas supply pipe 31 protrudes toward the inside of the chamber 15, and is connected to the gas supply nozzle 34. Although not shown in the drawings, the gas supply 1305012 is provided in a hollow disk shape, and a plurality of nozzle hole openings are formed in the plate surface. Thereby, the process gas can be uniformly supplied into the aforementioned chamber 15. Next, the action of drying the substrate W subjected to the cleaning treatment by the drying processing unit 9 having the above configuration will be described. 5 Fig. 3 is a timing chart showing the supply of the substrate W to the chamber 15, the switching of the switch control valve 25, the operation of the exhaust pump 24, and the supply of the process gas. The graph A in Fig. 4 is the relationship between the displacement amount φ per unit time in the chamber 15 in which the exhaust pump 24 is exhausted and the time, and the graph B shows the supply amount of the process gas controlled by the supply air flow control valve 32. The relationship with time. 10 The substrate W is supplied into the chamber 15 at time T1, but the process gas is supplied from the previous time T0. Further, although the exhaust pump 24 is actuated, since the switching control valve 25 is closed, the exhaust gas from the exhaust pump 24 does not act in the chamber 15. That is, there is no pressure reduction in the chamber 15. When the substrate W is supplied to the chamber 15 at time T1, the switch control valve 25 is opened and released, and the exhaust flow rate adjusting valve 26 is controlled to be gradually increased by φ from the predetermined opening degree, so that the amount of exhaust per unit time is increased. Further, the supply air flow rate control valve 32 is controlled to gradually reduce the supply amount of the process gas supplied into the chamber 15. While the substrate W is supplied into the chamber 15 at time T1, the energization of the heater 17 is started, and the inside of the chamber 15 is heated to the set temperature. Further, the heating by the heater 17 20 may be performed before the substrate W is supplied to the chamber 15. At the time T1 when the switch control valve 25 is opened and the pressure reduction in the chamber 15 is started, the supply amount of the process gas supplied into the chamber 15 reaches Q1 per unit time, whereby the pressure in the chamber 15 also rises. To pressure above atmospheric pressure: force. 10 1305012 Again, the pressure within 15 is detected by pressure detector 28. When the pressure in the chamber 15 becomes a predetermined pressure, the supply of the process gas is controlled so that the pressure within 15 does not rise any more. When the substrate W is supplied to the chamber 15 and the switch control valve 25 is opened and the decompression in the chamber 15 is started, the gas in the chamber (10) is rapidly discharged when the waste reduction is started. However, the process gas is supplied to the chamber 15 until it becomes a pressure that is not determined by the pressure sensing | § 28. Therefore, at the start of the depressurization, even if the pressure in the process gas "room 15" is rapidly lowered from φ 胄 15 , the pressure in the chamber 15 is slightly lowered, but it is not greatly lowered. Therefore, when the switch control valve 25 is opened at the start of pressure reduction, the pressure in the chamber 15 does not rapidly change and turbulence occurs, so that particles deposited in the chamber 15 and adhering to the inner surface can be prevented from being scattered in the chamber. 15 is attached to the substrate w. The supply amount of the process gas supplied to the chamber 15 is as shown in the graph 3 of Fig. 4, and the time from the start of the decompression in the chamber 15 is gradually decreased, and every time a predetermined time T2 is passed, each unit is passed. The supply of time is Q2. On the other hand, the exhaust amount per unit time of the exhaust pump 24 is gradually increased by the time τι as shown in the graph, and reaches νι at the time Τ2. The exhaust speed at this time can be controlled by the opening adjustment of the exhaust flow rate adjusting valve 26. Thus, by gradually reducing the supply of process gas into the chamber 15, 2〇 and gradually increasing the amount of exhaust in the chamber 15, the pressure in the chamber 15 during the time T2 is reduced to the pre-pressure, that is, suitable for the substrate. W The pressure of the drying process. From time T2 to time T3', the amount of depletion per unit time of the opening degree of the exhaust gas flow rate adjustment, and the supply amount Q2 per unit time of the gas supply of the gas supply flow rate control (4) 32 are continuously continued. Thereby, since the inside of the chamber 15 is maintained at a predetermined pressure reduction pressure, the substrate W can be dried under its reduced pressure. During the drying process of the substrate W, the supply of the process gas is performed at a supply amount of Q2 per 5 unit time, and the exhaust gas is a discharge amount VI which is an amount equal to the supply amount Q2. Therefore, in the drying process, the water vapor generated by the substrate W is discharged from the inside of the chamber 15 by the process gas exhausted by the exhaust amount VI, so that the drying treatment can be promoted. Further, in the meantime, since the pressure in the chamber 15 does not change, there is no possibility that turbulent flow occurs in the chamber 15 and particles are adhered to the 10 substrate W. Thus, when the drying process of the substrate W ends, the time T3 to the time T4, the exhaust gas flow rate adjusting valve 26 is gradually closed, and the switching control valve 25 is closed at time T4. Thereby, the exhaust gas per unit time in the chamber 15 by the exhaust pump 24 is gradually reduced from VI to zero. On the other hand, the supply amount of the process gas is gradually increased from 15 Q2 and is Q1 at time T4. Further, the pressure in the chamber 1 becomes φ, and when this is detected by the pressure detector 28 at time T5, the supply amount of the process gas is 〇. Thus, when the pressure in the chamber 15 returns to atmospheric pressure, the amount of exhaust per unit time in the chamber 15 is gradually reduced, and the supply amount per unit time of the process gas 20 is gradually increased. Therefore, when the chamber 15 returns to the atmospheric pressure, since the pressure in the chamber 15 does not rise rapidly, it is possible to prevent the particles remaining in the chamber 15 from scattering and adhering to the substrate W. Further, in the above-described embodiment, when the decompression in the room is started or the decompression state is returned to the atmospheric pressure in 12 1305012, the exhaust pump is actuated, and the switch control valve is switched, but the switch may not be provided. There is a switch control valve to control the start and stop of the exhaust pump. [Brief Description of the Drawings] Fig. 1 is a schematic explanatory view showing a substrate processing apparatus according to an embodiment of the present invention. φ Fig. 2 is a drying processing unit for drying a substrate. Fig. 3 is a time chart for explaining the actions of various machines installed in the drying processing unit. Fig. 4 is a graph showing the relationship between the amount of exhaust gas per unit time and the supply amount of process gas. 13 1305012 [Description of main component symbols] 1...Processing device 18 of the substrate...Heater controller 2...Box station 19...Temperature sensor - 3...Box 21...Control device - 4. Loading unit 23...exhaust pipe '5".unloading unit 24...exhaust pump• 7.··transfer unit 25...switch control valve 8...rotation washing processing unit 26... Exhaust flow rate adjustment valve 9...drying processing unit 28...pressure detector 11...machine 31...gas supply tube 12...machine arm 32...air supply flow control valve 15··· Chamber 33... Switching valve 16... Table 34... Gas supply nozzle • 17... Heater W.·Wire 14