471109 6587twf.doc/006 A7 B7 經濟部智慧財產局員工消費合作社印製 五、發明說明（p 本發明是有關於一種氮化矽層的沈積方法’且特別是 有關於一種增加氮化矽層的沈積選擇性的方法。 氮化矽，是一種在半導體製程中常見的介電材料。它 最主要應用是作爲氧化矽層之蝕刻罩幕，並藉著氮化矽層 不易被氧所滲透之優點，這層罩幕還可以作爲進行氧化層 製作時，防止晶片表面的主動區域遭受氧化的罩幕層，除 了這個應用以外，因爲氮化矽層不易被水氣所滲透，所以 已被廣泛地使用作爲半導體元件的保護層。也因爲氮化矽 層有這麼多的用途，因此氮化矽層在半導體製程中佔有一 極爲重要之地位。 以目前的反應條件，若同時在氧化矽層的表面與基底 表面上，分別沈積氮化矽層，在兩表面上分別所形成的氮 化矽層，其食近乎相等;。隨著半導體的技術日益進步， 如何將製程簡化已越來越重要，然而，習知方法並無法同 時在氧化矽層的表面與基底表面上，形成厚度不同的氮化 矽層，當需要不同厚度的氮化矽層時，並不能以單一沈積 步驟形成。 因此本發明提出一種增加氮化矽層沈積選擇比的方 法’亦即，增加氮化矽層形成在氧化矽層的表面與基底表 面上的厚度差異比値。 本發明提供一種增加氮化矽層的沈積選擇性的方法， 首先’提供一基底，形成一氧化矽層於一部份之基底上， 通入一 ΝΗ3氣體進行一表面處理，使^^113氣體流經基底與 氧化砂層之表面一段時間，之後，沈積氮化矽層於基底與 3 ------------* 裝--------訂----I----線& (請先閱讀背面之注意事項再填寫本頁) 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公爱） 經濟部智慧財產局員工消費合作社印製 471109 6587twf.doc/006 — _______B7 五、發明說明（ 氧化砂層上。 利用本發明利用一含氮氣體，較佳爲一 nh3氣體進行 一表面處理，將NH3氣體流經基底與氧化層之表面一段時 間，之後可利用單一沈積步驟，同時在氧化砂層的表面與 基底表面上，形成厚度不同的氣化砍層，並不需要藉由不 同之沈積步驟分別在氧化砂層的表面與基底表面上進行沈 積，因此，可將半導體製程簡化。 爲讓本發明之上述和其他目的、特徵、和優點能更明 顯易懂，下文特舉較佳實施例，並配合所附圖式，作詳細 說明如下： 圖式之簡單說明： 第1和2圖係依照本發明一較佳實施例同時形成氮化 矽層在氧化矽層表面上與基底表面上的製程剖面圖。 第3圖係表示不同的NH3氣體處理條件對氮化矽層厚 度差異比値的影響。 第4圖係分別量測氮化矽層在不同壓力下之厚度差異 比値。 第5圖係分別量測氮化矽層在不同反應氣體流速比下 之厚度差異比値。 圖式之標記說明： 100 :基底 102 :氧化矽層 104a、104b :氮化矽層 實施例 4 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） I I I I I----I ^---------------I I ^ L (請先閱讀背面之注意事項再填寫本頁) 471109 6 5 8 7 twf :/0 06 A7 B7 經濟部智慧財產局員工消費合作社印製 五、發明說明（多） 請參照第1圖，首先提供一基底100，此基底100較 佳爲半導體基底如矽基底。由於原生氧化層（未顯示）很容 易形成在基底100表面，因此爲了得到近乎純矽之表面’ 必須利用一系列之淸洗的步驟，去除附著於基底1〇〇上的 原生氧化層，此習知淸洗的步驟簡述如下：利用機械手臂 將基底100置入於RCA溶液淸洗槽10中以淸洗基底100， 其中RCA溶液包括氫氧化銨（NH4OH)、熱去離子水（Hot Deionized Water，HDIW)與雙氧水（H202 )等溶液，在共 沸的溫度下淸洗基底100,以去除基底100表面所產生的 原生氧化層。接著，將基底100置入快速熱、冷水淸洗（Hot Quick-Dump Rinse，HQDR)槽中，利用大量的去離子水快 速淸洗基底100上所殘留的RCA溶液。然後，再將基底1〇〇 置入於稀釋的氫氟酸（Dilute HF，DHF)槽中，進行稀釋 的氫氟酸（DHF)最後處理步驟，以去除基底100的原生氧 化層、有機物與微粒。 接著，在一部份基底100上形成氧化矽層102，此氧 化矽層102之形成方式例如爲利用熱氧化步驟將一部份之 基底100氧化。 請參照第2圖，利用一含氮氣體，較佳爲一 NH3氣體， 進行一表面處理之步驟，使NH3氣體在形成氧化矽層iQ2 之基底100上通入一段時間，通入NH3氣體的時間可隨製 程需要而疋。在利用NH3氣體進行一'表面處理一^段時間 後，進行一沈積步驟，分別同時在基底100與氧化矽層1()2 上，形成氮化矽層104a與氮化矽層104b。其中，其中較 5 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） I I I--— — — — — It ^ - — III· — — ! « — IlIIII — · (請先閱讀背面之注意事項再填寫本頁) 471109 經濟部智慧財產局員工消費合作社印製 五、發明說明（斗） 佳的NH3氣體之表面處理步驟的溫度約介於600。(：至1100 之間，而其較佳的壓力範圍約介於0.3 torr至760 torr 之間，另外，氮化砂層104a與氮化砂層l〇4b之沈積壓力 可等於或小於0.3 torr，若使用之反應氣體爲NH3與 SiH2Cl2 時，其反應氣體之流速比可在約等於或大於3:1之條件下 進行沈積。 由實驗結果得知，在利用nh3氣體進行一表面處理一 段時間後，所形成之氮化矽層104a的厚度會比氮化矽層 l〇4b厚，而氮化砂層l〇4a與104b之厚度差異比値（thickness difference ratio)可達50 %-120 %。其中，氮化砂層厚度差 異比値的計算方式爲（Tsi-Tox)/[(Tsi+Tox)/2]，Tsi爲沈積在 基底100表面上的氮化矽層厚度，亦即爲氮化矽層l〇4a之 厚度；Tox爲沈積在氧化矽層表面上的氮化矽層厚度，亦 即爲氮化矽層104b之厚度。當欲增加氮化矽層i〇4a與104b 的厚度差異比値時，可降低沈積壓力比，或提高反應氣體 的流速比，而通入NH3氣體的時間可隨製程需要而調整。 請參照第3圖，由實驗結果證明，經由>^3氣體處理 後’所得到的氮化矽層厚度差異比値，比沒有經過NH3氣 體處理之厚度差異比値大。上述之氮化矽層厚度差異比値 皆爲（Tsi-Tox)/[(Tsi+Tox)/2]，Tsi爲沈積在基底1〇〇表面上 的氮化砂層厚度，亦即爲氮化砂層l〇4a之厚度；Tox爲沈 積在氧化矽層表面上的氮化矽層厚度，亦即爲氮化矽層 104b之厚度。 第4圖係分別量測氮化矽層在不同壓力下之氮化矽層 6 I---— I! ^ -----··!1 訂— —--!線- (請先閱讀背面之注意事項再填寫本頁) 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 471109 五、發明說明（f) 厚度差異比値，其中0.125 torr壓力下之氮化矽層厚度差 異比値爲最大，可知壓力越低氮化砍層厚度差異比値越 大。 第5圖係分別量測氮化矽層在不同反應氣體流速比下 之厚度差異比値。其中，圖示中之反應氣體流速比係爲NH3 與sm2ci2之流速比，由實驗結果可知，反應氣體流速比 越大，氮化矽層厚度差異比値越大。 利用本發明利用nh3氣體進行一表面處理，將nh3氣 體流經基底與氧化層之表面一段時間，之後可利用單一沈 積步驟，同時在氧化矽層的表面與基底表面上，形成厚度 不同的氮化矽層，當需要不同厚度的氮化膜時，可藉由單 一沈積步驟形成，因此，可將半導體製程簡化。 雖然本發明已以較佳實施例揭露如上，然其並非用以 限定本發明，任何熟習此技藝者，在不脫離本發明之精神 和範圍內，當可作各種之更動與潤飾，因此本發明之保護 範圍當視後附之申請專利範圍所界定者爲準。 ϊ— I I I ---j 裝！卜 ί — 訂·！ 1 — — 画—線 < (請先閱讀背面之注意事項再填寫本頁) 經濟部智慧財產局員工消費合作社印製 7 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐）471109 6587twf.doc / 006 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the invention Selective deposition method. Silicon nitride is a common dielectric material used in semiconductor processes. Its main application is as an etching mask for the silicon oxide layer, and the advantage of the silicon nitride layer is not easily penetrated by oxygen. This layer of mask can also be used as a mask layer to prevent the active area of the wafer surface from being oxidized during the production of the oxide layer. In addition to this application, the silicon nitride layer is not easily penetrated by moisture, so it has been widely used. As a protective layer for semiconductor elements. Because silicon nitride layers have so many uses, silicon nitride layers occupy a very important position in semiconductor manufacturing processes. Under the current reaction conditions, if the surface of the silicon oxide layer and the silicon oxide layer are simultaneously On the surface of the substrate, a silicon nitride layer is separately deposited, and the silicon nitride layers formed on the two surfaces are almost equal. With the increasing technology of semiconductors Steps, how to simplify the process has become more and more important. However, conventional methods cannot form silicon nitride layers with different thicknesses on the surface of the silicon oxide layer and the surface of the substrate at the same time. When different thicknesses of silicon nitride layers are required It cannot be formed in a single deposition step. Therefore, the present invention proposes a method for increasing the silicon nitride layer deposition selectivity ratio, that is, increasing the thickness difference ratio of the silicon nitride layer formed on the surface of the silicon oxide layer and the surface of the substrate. The present invention provides a method for increasing the deposition selectivity of a silicon nitride layer. First, a substrate is provided, a silicon oxide layer is formed on a part of the substrate, and a NH 3 gas is passed through to perform a surface treatment to make ^^ 113 gas. After passing through the surface of the substrate and the oxidized sand layer for a period of time, a silicon nitride layer is deposited on the substrate and 3 ------------ * 装 -------- Order ---- I ---- Line & (Please read the notes on the back before filling out this page) This paper size applies to China National Standard (CNS) A4 (210 X 297 public love) Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 471109 6587twf.doc / 006 — _______B7 V. Invention Description (on an oxidized sand layer. Using the present invention, a nitrogen-containing gas, preferably an nh3 gas, is used for a surface treatment, and the NH3 gas is flowed over the surface of the substrate and the oxide layer for a period of time. A single deposition step can then be used at the same time during oxidation The formation of vaporized cutting layers with different thicknesses on the surface of the sand layer and the surface of the substrate does not require separate deposition steps on the surface of the oxide sand layer and the surface of the substrate, so the semiconductor process can be simplified. The above and other objects, features, and advantages of the invention can be more clearly understood. The preferred embodiments are described below in detail with the accompanying drawings as follows: Brief description of the drawings: Figures 1 and 2 are in accordance with A cross-sectional view of a process for forming a silicon nitride layer on the surface of the silicon oxide layer and the surface of the substrate at the same time according to a preferred embodiment of the present invention. Figure 3 shows the effect of different NH3 gas treatment conditions on the thickness difference ratio 矽 of the silicon nitride layer. Figure 4 measures the thickness difference ratio 矽 of the silicon nitride layer under different pressures. Figure 5 measures the thickness difference ratio 矽 of the silicon nitride layer under different reaction gas flow rate ratios. Explanation of the marks in the drawing: 100: substrate 102: silicon oxide layer 104a, 104b: silicon nitride layer Example 4 This paper size applies to China National Standard (CNS) A4 specification (210 X 297 mm) IIII I ---- I ^ --------------- II ^ L (Please read the notes on the back before filling this page) 471109 6 5 8 7 twf: / 0 06 A7 B7 Intellectual Property Bureau, Ministry of Economic Affairs Printed by the employee consumer cooperative V. Description of the invention (multiple) Please refer to FIG. 1 first to provide a substrate 100, which is preferably a semiconductor substrate such as a silicon substrate. Since a native oxide layer (not shown) is easily formed on the surface of the substrate 100, in order to obtain a nearly pure silicon surface, a series of cleaning steps must be used to remove the native oxide layer attached to the substrate 100. The steps of knowing washing are briefly described as follows: The substrate 100 is placed in the RCA solution washing tank 10 by using a robot arm to wash the substrate 100. The RCA solution includes ammonium hydroxide (NH4OH) and hot deionized water (Hot Deionized Water). (HDIW) and hydrogen peroxide (H202) and other solutions, the substrate 100 is rinsed at an azeotropic temperature to remove the primary oxide layer generated on the surface of the substrate 100. Next, the substrate 100 is placed in a Hot Quick-Dump Rinse (HQDR) bath, and a large amount of deionized water is used to quickly rinse the RCA solution remaining on the substrate 100. Then, the substrate 100 is placed in a diluted hydrofluoric acid (Dilute HF, DHF) tank, and the diluted hydrofluoric acid (DHF) final processing step is performed to remove the native oxide layer, organic matter and particles of the substrate 100. . Next, a silicon oxide layer 102 is formed on a part of the substrate 100. The silicon oxide layer 102 is formed, for example, by using a thermal oxidation step to oxidize a part of the substrate 100. Please refer to FIG. 2, using a nitrogen-containing gas, preferably an NH3 gas, to perform a surface treatment step, so that the NH3 gas is passed on the substrate 100 forming the silicon oxide layer iQ2 for a period of time, and the time for passing the NH3 gas. According to the needs of the process. After performing a 'surface treatment with NH3 gas for a period of time, a deposition step is performed to simultaneously form a silicon nitride layer 104a and a silicon nitride layer 104b on the substrate 100 and the silicon oxide layer 1 () 2, respectively. Among them, more than 5 paper sizes are applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) II I --- — — — — It ^-— III · — —! «— IlIIII — · (Please first (Please read the notes on the back and fill in this page) 471109 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the invention (bucket) The temperature of the surface treatment step of the best NH3 gas is about 600. (: To 1100, and its preferred pressure range is about 0.3 torr to 760 torr. In addition, the deposition pressure of the nitrided sand layer 104a and the nitrided sand layer 104b may be equal to or less than 0.3 torr. When the reaction gas is NH3 and SiH2Cl2, the flow rate ratio of the reaction gas can be deposited under the conditions of approximately equal to or greater than 3: 1. From the experimental results, it is known that the formation of nh3 gas after a surface treatment for a period of time, The thickness of the silicon nitride layer 104a will be thicker than that of the silicon nitride layer 104b, and the thickness difference ratio of the nitrided sand layers 104a and 104b may be 50% -120%. Among them, the nitride The thickness difference ratio 差异 of the sand layer is calculated as (Tsi-Tox) / [(Tsi + Tox) / 2], where Tsi is the thickness of the silicon nitride layer deposited on the surface of the substrate 100, which is the silicon nitride layer 104a. Tox is the thickness of the silicon nitride layer deposited on the surface of the silicon oxide layer, that is, the thickness of the silicon nitride layer 104b. When it is desired to increase the thickness difference ratio of the silicon nitride layers i04a and 104b, Reduce the deposition pressure ratio, or increase the flow rate ratio of the reaction gas, and the time of passing NH3 gas can be changed with The process needs to be adjusted. Please refer to Figure 3, and it is proved from the experimental results that the thickness difference ratio 矽 of the silicon nitride layer obtained after > ^ 3 gas treatment is larger than the thickness difference ratio 値 which is not treated with NH3 gas. The thickness difference ratios of the above silicon nitride layers are all (Tsi-Tox) / [(Tsi + Tox) / 2]. Tsi is the thickness of the nitrided sand layer deposited on the surface of the substrate 100, that is, the nitrided sand layer. l04a thickness; Tox is the thickness of the silicon nitride layer deposited on the surface of the silicon oxide layer, that is, the thickness of the silicon nitride layer 104b. Figure 4 shows the nitrogen of the silicon nitride layer under different pressures. Siliconized layer 6 I ---- I! ^ ----- · !! 1 Order -----! Line-(Please read the precautions on the back before filling this page) This paper size applies Chinese national standards ( CNS) A4 specification (210 X 297 mm) 471109 V. Description of the invention (f) Thickness difference ratio 値, where the thickness difference ratio 矽 of the silicon nitride layer under the pressure of 0.125 torr is the largest. The larger the difference ratio 値. Figure 5 measures the thickness difference ratio 矽 of the silicon nitride layer under different reaction gas flow rate ratios. Among them, The flow rate ratio of the reaction gas in the figure is the flow rate ratio of NH3 and sm2ci2. It can be known from the experimental results that the larger the flow rate ratio of the reaction gas, the larger the difference ratio 矽 of the thickness of the silicon nitride layer. The nh3 gas flows through the surface of the substrate and the oxide layer for a period of time, and then a single deposition step can be used to form a silicon nitride layer with different thicknesses on the surface of the silicon oxide layer and the surface of the substrate at the same time. The film can be formed by a single deposition step, so that the semiconductor process can be simplified. Although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and retouches without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be determined by the scope of the attached patent application. ϊ— I I I --- j equipment!卜 — Order! 1 — — Draw — Thread (Please read the notes on the back before filling out this page) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 7 This paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) )