經濟部中央橾準局員工消費合作社印装 411S64 3130twf.doc/006 A? B7 五、發明説明（/ ) 本發明是有關於一種積體電路元件隔離結構之製造方 法，且特別是有關於一種化學機械硏磨法（Chemical Mechanical Polishing，CMP)，可用於製造淺溝渠隔離結構 (Shallow Trench Isolation, STI)。 習知的淺溝渠隔離結構亦是一種普遍的元件隔離方 法，一般使用氮化砂作爲硬罩幕，以非等向性（Anisotropic) 蝕刻法在半導體基底中挖出溝渠。然後將溝渠塡滿氧化矽 層，再於氧化矽層上進行化學機械硏磨法，而形成元件隔 離結構，且此結構具有與原基底等高之表面。 第1圖至第3圖係繪示習知一種淺溝渠隔離結構之製 造流程剖面圖。 請參照第1圖，在矽基底10上形成氧化層22，其中 此氧化層22作爲塾氧化層(Pad Oxide Layer)，並用於保護 基底的表面，而於後續閘極氧化層形成之前移去。之後進 行化學氣相沈積法(CVD)形成氮化矽層24。然後，在氮化 矽層24上沈積光阻層28用以定義溝渠，接著經微影製程 而形成罩幕28，再依序蝕刻氮化矽層24、墊氧化層22、 及矽基底10。完成在基底上形成一溝渠30後，再移除蝕 刻光阻層28。 請參照第2圖，然後使用熱氧化法，在溝渠中形成一 襯氧化層31(Linear Oxide)。接著，將溝渠30塡滿氧化矽 層 32，比如以砂酸四乙酯(tetra-ethyl-ortho-silicate，TE0S) 爲氣源，使用常壓化學氣相沈積法（Atmospheric Pressure Chemical Vapor Deposition，APCVD)沈積，並使氧化砂溢出 3 本紙張尺度通用中國國家搮準（CNS ) A4規格（210X297公釐） i n 裝 ,~n n 1— η I. I I 線 ,· Ϊ (請先閲讀背面之注意事項再填寫本頁) 經濟部中央標準局員工消费合作社印裝 411564 3 130twffdoc/006 A7 _B7_ 五、發明説明（之） 溝渠。因氧化砂層需經密實化(Densification)步驟，比如在 溫度1100°C下，進行時間約10〜60分鐘，而經密實化後， 氧化矽層會產生收縮。 請參照第3圖，在密實化之後，則以化學機械硏磨法 去除氮化矽層24上之氧化矽層32，而以氮化矽層24爲硏 磨終點，留下溝渠區中的_化插塞34。 然而，化學機械硏磨法進行時，由於氧化插塞較氮化 矽層爲軟，因此在同一步驟只能有一組硏磨參數的情況之 下，氮化砍層24和氧化插塞34若同時硏磨時，氧化插塞 34會有輕微的凹入現象，而且氮化矽的硬度又大，容易在 進行化學機械硏磨的步驟時，會對氧化插塞的表面造成嚴 重刮傷。如此在後續形成之閘極和金屬線的步驟時，容易 在刮痕中殘留金屬，而導致金屬線橋接(bridge)的現象* 因此本發明的主要目的就是在提供一種化學機械硏磨 法，可用於淺溝渠隔離結構，減少氧化插塞表面的刮傷情 形，以解決習知之缺點。 根據本發明的目的，提出一種化學機械硏磨法，包括 在沈積完氮化矽層之後加入一表面處理步驟，包括用離子 或氣體轟擊氮化矽層表面，改變其部份化學結構，使得氮 化砂層表面變得較軟’在進fr cmp時避免傷到氧化插塞 的表面，可以提高良率 爲讓本發明之上述目的、特徵、和優點能更明顯易懂， 下文特舉一較佳實施例，並配合所附圖式，作詳細說明如 下： 4 本紙張尺度適用中國國家橾準（CNS ) Α4規格（210X297公董） I---------私衣------ί1τ----- I"Τ 線 • · ， (請先閲讀背面之注意事項再填寫本頁) 經濟中央標準局員工消費合作社印製 411564 3130twf.doc/006 A7 B7 五、發明説明（>) 圖式之簡單說明： 第1圖至第3圖係繪示習知一種淺溝渠隔離結構之製 造流程剖面圖：以及 第4圖至第7圖係繪示依照本發明一較佳實施例的一 種淺溝渠隔離結構之製造流程剖面圖。 圖式之標記說明：^ 10、110 :矽基底 22、122 :墊氧化層 24、124 :氮化矽層 126 :氮化矽層表面處理 28、128 :光阻層 30、 130 :溝渠 31、 131 :襯氧化層 32、 132 :氧化層 34、134 :氧化插塞 實施例 第4圖至第7圖係繪示依照本發明一較佳實施例的一 種淺溝渠隔離結構之製造流程剖面圖。 請參照第4圖，在矽基底110上彤成氧化層122作爲 墊氧化層，並用於保護基底的表面，以免受後續製程的破 壞。這層氧化層122可以用熱氧化法來形成，厚度約 50〜500A。之後以化學氣相沈積法，形成氮化矽層124。 接著做氮化矽層表面處理，例如用離子植入法將砷 (As)…等植入氮化矽層124表面、用氬氣（Ar)轟擊 5 ----------1--------IT------f ^ 1 - - - - . (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圉家橾準（CNS > A4規格（210X297公釐） 經潦部中央標準局貝工消費合作社印裝 411564 3130twf.doc/006 A7 B7 五、發明説明（y) 、 (bombardment氮化砂層表面或用氧電紫對氮化砂層表面進 行灰化反應(ashing reaction)，或其他化學、物理方法來破 壞氮化矽層124表面的結構，使得氮化矽層表面的硬度變 得較軟。如此在接著做CMP時，因爲氮化矽和氧化插塞 的硬度較接近之後，比較不會在後續硏磨時，有上述習知 容易刮傷表面的缺點。‘ 接著，後面的步驟都和習知的一模一樣。請參照第5 圖，然後在氮化矽層124上沈積光阻層128用以定義溝渠， 接著經微影蝕刻製程而形成罩幕128,再依序蝕刻氮化矽 層124、墊氧化層122、及矽基底110。在基底上形成一溝 渠130後，再移除蝕刻光阻層128。 請參照第6圖，然後使用熱氧化法，在溝渠中形成一 襯氧化層131。接著，比如以矽酸四乙酯爲氣源，使用常 壓化學氣相沈積法將溝渠130塡滿矽氧化層132,再經密 實化步驟，使TE0S氧化層產生收縮》 請參照第7圖，在密實化之後，則以化學機械硏磨法 去除氮化矽層124上之TEOS氧化層132,而以氮化矽層124 爲硏磨終點，留下溝渠區中的氧化插塞134。因爲前述已 經有對氮化矽層做表面處理，所以在這可以得到表面較平 整且刮痕較少的氧化插塞表面。 由上述本發明較佳實施例可知，應用本發明具有避免 氧化插塞在進行CMP步驟時被刮傷之優點。 雖然本發明已以一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 6 本紙張尺度速用中國囷家#準（CNS > A4規格（210X297公釐） I J.-------裝--------I 訂-----II 線 _ *- . ' (請先閱讀背面之注意事項再填寫本頁) 411564 3 130twf,doc/006 A7 B7 五、發明説明（4) 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。 I--------^-- -** -- (請先聞讀背面之注意事ί;再填寫本頁) .1Τ 線 經濟部中央標準局貝工消費合作社印製 本紙浪尺度適用中國國家揉準（CNS ) Α4規格（2丨0X297公釐）Printed by the Consumers' Cooperatives of the Central Government Bureau of the Ministry of Economic Affairs 411S64 3130twf.doc / 006 A? B7 V. Description of the Invention (/) The present invention relates to a method for manufacturing an integrated circuit component isolation structure, and more particularly to a chemical Mechanical Honing (CMP) can be used to make Shallow Trench Isolation (STI). The conventional shallow trench isolation structure is also a common element isolation method. Generally, nitrided sand is used as a hard cover. Anisotropic etching is used to dig trenches in the semiconductor substrate. The trench is then filled with a silicon oxide layer, and a chemical mechanical honing method is performed on the silicon oxide layer to form a component isolation structure, and the structure has a surface equal to the original substrate. Figures 1 to 3 are sectional views showing the manufacturing process of a conventional shallow trench isolation structure. Referring to FIG. 1, an oxide layer 22 is formed on a silicon substrate 10. The oxide layer 22 serves as a pad oxide layer and is used to protect the surface of the substrate, and is removed before the subsequent gate oxide layer is formed. Thereafter, a chemical vapor deposition (CVD) method is performed to form a silicon nitride layer 24. Then, a photoresist layer 28 is deposited on the silicon nitride layer 24 to define a trench, and then a mask 28 is formed through a lithography process, and then the silicon nitride layer 24, the pad oxide layer 22, and the silicon substrate 10 are sequentially etched. After a trench 30 is formed on the substrate, the etching resist layer 28 is removed. Referring to Figure 2, a thermal oxidation method is used to form a liner oxide layer 31 (Linear Oxide) in the trench. Next, the trench 30 is filled with a silicon oxide layer 32. For example, tetra-ethyl-ortho-silicate (TE0S) is used as a gas source, and Atmospheric Pressure Chemical Vapor Deposition (APCVD) is used. ) Deposit and make the oxidized sand overflow. 3 This paper size is in accordance with China National Standard (CNS) A4 (210X297 mm) in the package, ~ nn 1— η I. II line, · Ϊ (Please read the precautions on the back first (Fill in this page again) Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs 411564 3 130twffdoc / 006 A7 _B7_ V. Description of the Invention (of) Ditch. Because the oxidized sand layer needs to undergo a densification step, for example, at a temperature of 1100 ° C, the process takes about 10 to 60 minutes, and after the densification, the silicon oxide layer will shrink. Please refer to Figure 3. After compaction, the silicon oxide layer 32 on the silicon nitride layer 24 is removed by chemical mechanical honing, and the silicon nitride layer 24 is used as the honing end point, leaving _ in the trench area.化 plug 34. However, when the chemical mechanical honing method is performed, since the oxide plug is softer than the silicon nitride layer, under the condition that there can be only one set of honing parameters in the same step, if the nitride cutting layer 24 and the oxide plug 34 are simultaneously During honing, the oxidation plug 34 has a slight concave phenomenon, and the hardness of the silicon nitride is large. It is easy to cause serious scratches on the surface of the oxidation plug during the step of chemical mechanical honing. In this way, in the subsequent steps of forming the gate electrode and the metal wire, it is easy to leave metal in the scratches, resulting in the phenomenon of bridging the metal wire. Therefore, the main purpose of the present invention is to provide a chemical mechanical honing method, which can be used. In the shallow trench isolation structure, the scratch of the surface of the oxidation plug is reduced to solve the conventional shortcomings. According to the purpose of the present invention, a chemical mechanical honing method is proposed, which includes adding a surface treatment step after depositing the silicon nitride layer, including bombarding the surface of the silicon nitride layer with ions or gas to change a part of its chemical structure so that nitrogen The surface of the sand layer becomes softer ', which avoids damaging the surface of the oxidized plug when entering fr cmp, which can improve the yield to make the above-mentioned objects, features, and advantages of the present invention more obvious and easy to understand. The examples, combined with the attached drawings, are described in detail as follows: 4 This paper size applies to China National Standards (CNS) A4 specifications (210X297 public directors) I --------- Private clothing ---- --ί1τ ----- I " T line • ·, (Please read the notes on the back before filling this page) Printed by the Central Economic Bureau Standards Consumer Cooperatives 411564 3130twf.doc / 006 A7 B7 V. Description of the invention ( >) Brief description of the drawings: Figures 1 to 3 are sectional views showing the manufacturing process of a conventional shallow trench isolation structure: and Figures 4 to 7 are drawings showing a preferred implementation according to the present invention Example of a manufacturing process for a shallow trench isolation structure Fig. Symbols of the drawings: ^ 10, 110: silicon substrate 22, 122: pad oxide layer 24, 124: silicon nitride layer 126: silicon nitride layer surface treatment 28, 128: photoresist layer 30, 130: trench 31, 131: lining oxide layer 32, 132: oxide layer 34, 134: oxidized plug. Embodiments 4 to 7 are cross-sectional views showing a manufacturing process of a shallow trench isolation structure according to a preferred embodiment of the present invention. Referring to FIG. 4, an oxide layer 122 is formed on the silicon substrate 110 as a pad oxide layer, and is used to protect the surface of the substrate from being damaged by subsequent processes. This oxide layer 122 can be formed by a thermal oxidation method and has a thickness of about 50 to 500 A. Then, a chemical vapor deposition method is used to form a silicon nitride layer 124. Next, the silicon nitride layer is surface-treated, for example, arsenic (As) ... is implanted on the surface of the silicon nitride layer 124 by ion implantation, and bombarded with argon (Ar) 5 ---------- 1 -------- IT ------ f ^ 1----. (Please read the notes on the back before filling out this page) This paper size is applicable to China Standards (CNS > A4 Specifications (210X297 mm) Printed by the Central Bureau of Standards of the Ministry of Industry and Commerce of the People's Republic of China, 411564 3130twf.doc / 006 A7 B7 V. Description of the invention (y), (bombardment surface of the nitrided sand layer or the surface of the nitrided sand layer with oxygen electro violet An ashing reaction or other chemical and physical methods are used to destroy the structure of the surface of the silicon nitride layer 124, so that the hardness of the surface of the silicon nitride layer becomes softer. Therefore, during the subsequent CMP, the silicon nitride After being closer to the hardness of the oxidation plug, it is less likely that the conventional method will easily scratch the surface during subsequent honing. 'Next, the subsequent steps are exactly the same as the conventional method. Please refer to Figure 5 and then A photoresist layer 128 is deposited on the silicon nitride layer 124 to define a trench, and then a lithography process is performed to form a mask 128. The silicon nitride layer 124, the pad oxide layer 122, and the silicon substrate 110 are sequentially etched. After a trench 130 is formed on the substrate, the photoresist layer 128 is removed. Please refer to FIG. 6, and then use a thermal oxidation method in the trench. A lining oxide layer 131 is formed in the substrate. Then, for example, using tetraethyl silicate as a gas source, the trench 130 is filled with the silicon oxide layer 132 using atmospheric pressure chemical vapor deposition, and then the densification step is performed to generate a TEOS oxide layer. Shrinking Please refer to Figure 7. After compaction, the TEOS oxide layer 132 on the silicon nitride layer 124 is removed by chemical mechanical honing, and the silicon nitride layer 124 is used as the honing end point, leaving the trench area. Oxide plug 134. Because the silicon nitride layer has been surface-treated as described above, an oxide plug surface with a flatter surface and less scratches can be obtained here. As can be seen from the foregoing preferred embodiments of the present invention, the present invention is applicable. The invention has the advantage of preventing the oxidation plug from being scratched during the CMP step. Although the invention has been disclosed as above with a preferred embodiment, it is not intended to limit the invention. Anyone skilled in the art will not depart from the invention. Fine 6 Paper Ruler Dossier China Standard #CNS > A4 (210X297mm) I J .------- installation -------- I order ----- II line_ *- . '(Please read the notes on the back before filling this page) 411564 3 130twf, doc / 006 A7 B7 V. Description of the invention (4) Within the scope of God and God, various modifications and retouching can be made, so the protection of the present invention The scope shall be determined by the scope of the attached patent application. I -------- ^--**-(Please read the notes on the back first; then fill out this page) .1Τ Printed by the Central Standards Bureau of the Ministry of Economic Affairs Applicable to China National Standard (CNS) Α4 (2 丨 0X297 mm)