經濟部中央標準局員工消費合作社印裝 401462 A7 B7 五、發明説明（/ ) 本發明係為一種可降低孔道蝕刻期間鋁網損失之氮化 鈦沈積方法，為一半導體製程之形成氮化鈦層的新方法， 可降低底層之鋁銅金屬遭到不當蝕刻所衍生之金屬步階覆 蓋效果較差以及接觸阻抗不穩定之問題者。 按現今半導體技術上除了使用次微米或深次微米製程 改進之外，對於垂直空間之有效運用方面，亦為朝著更多 層金屬方面改進，以達到更高密度之效果者，而各層金屬 間之相互連接，概以第一金屬層與第二金屬層間之相互連 接方式為例，為如第二圖所示，即在依序形成有1 5 0 0 A之鈦層（Ti〉、4000A之鋁銅金屬（AlCu) 以及250A之氮化鈦（TiN)之第一金屬層上方，經 形成一適當厚度之絕緣層（IMD)後，為經孔道（VI A )光罩之相關步驟，對該絕縁層（I M D )進行蝕刻形 成可與該第一金屬層相通之孔道（VIA)，其次再重覆 進行類似於前述第一金屬層之T i、A 1 C u及T i N金 屬之沈積步驟，以在該孔道（V I A)之内部及外圍位置 形成由1500A之鈦層（Ti) 、8 0 00A之鋁銅金 屬（AlCu)以及250A之氮化鈦（TiN)所組成 之第二金屬層，而藉前述孔道（VIA)達到連接上、下 金屬層之效果者。 惟在上述習知製程中，於孔道（V I A )蝕刻期間以 及透過離子水（D I )進行清潔之步驟時，即容易導致第 一金屬層遭到不當過蝕刻，亦即致使如第二圖該第一層鋁 -3- 本紙張度適用中國國家標準（CNS ) A4規格（210X297公釐） ----------tu”-裝—1 (請先閲讀背面之注意事項再填寫本頁)Printed by the Consumers' Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs 401462 A7 B7 V. Description of the Invention (/) The present invention is a titanium nitride deposition method that can reduce the loss of aluminum mesh during channel etching, and forms a titanium nitride layer for a semiconductor process The new method can reduce the problem of poor coverage and unstable contact resistance of the underlying aluminum and copper metal caused by improper etching. According to the current semiconductor technology, in addition to the use of sub-micron or deep sub-micron process improvements, the effective use of vertical space is also improved towards more layers of metal to achieve a higher density effect, and each layer of metal For the mutual connection, the connection between the first metal layer and the second metal layer is taken as an example. As shown in the second figure, a titanium layer (Ti>, 4000A Above the first metal layer of aluminum copper metal (AlCu) and titanium nitride (TiN) of 250A, after forming an insulating layer (IMD) of appropriate thickness, it is a related step of passing through the aperture (VI A) photomask. The insulating layer (IMD) is etched to form a via (VIA) that can communicate with the first metal layer, and then Ti, A 1 Cu, and T i N metals are deposited again similarly to the aforementioned first metal layer. Steps to form a second metal layer consisting of 1500A titanium layer (Ti), 800A aluminum copper (AlCu), and 250A titanium nitride (TiN) inside and outside the via (VIA). Through the aforementioned via (VIA) to achieve the effect of connecting the upper and lower metal layers However, in the above-mentioned conventional manufacturing process, during the etching of the vias (VIA) and the cleaning step through ionized water (DI), it is easy to cause the first metal layer to be improperly over-etched, which results in the second figure. The first layer of aluminum-3- This paper is in accordance with China National Standard (CNS) A4 specification (210X297 mm) ---------- tu "-pack—1 (please read the precautions on the back first) (Fill in this page)
、1T -，'•-丨.^ 經濟部中央標準局員工消費合作杜印製 401462 A7 __________ B7 五、發明説明（v) 銅金屬（A 1 Cu)產生標示"X"深度範圍之〃過蝕刻 〃損失，此舉，導致孔道（V I A)深度過深而衍生後續 第二層金屬之步階覆蓋（STEP COVERAGE)效果較差，此可由 第二圖該上層鋁銅金屬（A 1 C u)對應於孔道（V I A )内部之沈積厚度較薄且呈大彎曲曲度即為一例，且鋁銅 金屬損失增加之下，亦致使第一、第二層金屬間之接觸阻 抗（Rc— v i a)呈現相當不穩定之現象，是以，此等 孔道蝕刻作業之鋁銅遭不當過蝕刻之問題，應有予以改善 之必要。 本發明人鑑於傳統製程所衍生之缺點乃經悉心地試驗 與研究並一本鍥而不捨之發明精神，終發明出一種可降低 孔道蝕刻期間鋁銅損失之氮化鈦沈積方法，主要為一種可 在相同之孔道蝕刻步驟下，僅改變覆蓋在鋁銅金屬表層之 氮化鈦層的形成方式，而藉此等方式令氮化鈦具有較佳的 強度及較佳的抗腐蝕性，據以使孔道蝕刻之際，達到降低 對鋁銅金屬過蝕刻之問題，使得鋁銅金屬之損失降低者。 本發明之主要目的在於提供一種可降低孔道蝕刻期間 鋁銅損失之氮化鈦沈積方法，主要為令氮化鈦形成之步驟 分成兩步驟進行，第一步驟為在無氮氣之環境下，僅在氬 氣環境下進行數秒鐘之沈積，由於無氮氣之作用下，即在 鋁銅金屬表面形成一較佳強度及抗腐蝕性較佳的鈦層，其 後，則為在反應室中加入氮氣而進行一般形成氮化鈦之步 驟，亦即為令本發明之兩步驟作業下，為形成含鈦層及氮 -4- 本紙張尺度適用中國國家標準（CNS ) A4規格（210X297公嫠） (請先閲讀背面之注意事項再填寫本頁) .—裝---、 1T-， '•-丨. ^ Consumption cooperation between employees of the Central Bureau of Standards of the Ministry of Economic Affairs 401462 A7 __________ B7 V. Description of the invention (v) Copper metal (A 1 Cu) produced a mark " X " Etching loss is caused by this. As a result, the depth of the via (VIA) is too deep and the subsequent step coverage of the second layer of metal (STEP COVERAGE) is poor. This can be corresponding to the upper layer of aluminum copper metal (A 1 C u) in the second picture. As an example, the deposition thickness inside the via (VIA) is relatively thin and has a large bending curvature, and the increase in the loss of aluminum and copper metal has also caused the contact resistance (Rc— via) between the first and second layers of metals to be comparable. The unstable phenomenon is that the aluminum and copper in these channel etching operations are improperly over-etched, and it is necessary to improve them. In view of the disadvantages derived from the traditional process, the inventor has carefully studied and researched and persevered the spirit of the invention, and finally invented a titanium nitride deposition method that can reduce the loss of aluminum and copper during channel etching, mainly a method that can In the channel etching step, only the formation method of the titanium nitride layer covering the surface of the aluminum-copper metal is changed, and in this way, the titanium nitride has better strength and better corrosion resistance, so that the channel is etched. At this time, the problem of reducing over-etching of aluminum copper metal and reducing the loss of aluminum copper metal is achieved. The main object of the present invention is to provide a titanium nitride deposition method capable of reducing the loss of aluminum and copper during the etching of a channel. The method mainly consists of dividing the step of forming titanium nitride into two steps. The first step is under a nitrogen-free environment, and only Deposition for a few seconds under an argon atmosphere. As a result of the absence of nitrogen, a titanium layer with better strength and better corrosion resistance is formed on the surface of aluminum and copper metal. Thereafter, nitrogen is added to the reaction chamber. The general titanium nitride forming step is performed, which is to make the titanium-containing layer and nitrogen in the two-step operation of the present invention. 4- The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 cm). (Please (Please read the notes on the back before filling out this page.)
、1T 401462 A7 B7 五、發明説明〇 ) 化鈦層之雙層構造 > 此舉，即可藉該鈦層而降低下層鋁銅 金屬週蝕刻之程度者。 本發明之次一目的在於提供一種可降低孔道蝕刻期間 鋁銅損失之氮化鈦沈樓方法，上述方式不僅可達到不致使 得鋁銅金屬過度損失之外，亦一併使得後續金屬具有較佳 步階覆蓋效果以及具有穩定孔道接觸阻抗之效果者。 為使貴審查委員能進一步暸解本發明之方法，特徵 及其他目的，玆附以圖式詳細說明如后： (―)·圖式部份： 第一圖：係本發明之兩金屬層間之剖面示意圖。 第二圖：係習知兩金屬層間之剖面示意圖。 第三圜：係本發明氮化鈦製程下之各批晶片之孔道阻値分 佈圜。 第四圖：係習知氮化鈦製程下之各批晶片之孔道阻値分佈 圖。 (二）·圖號部份： (T i )鈦層 （A 1 C u )鋁銅金屬 (TiN)氮化鈦 （IMD)絕緣層 經濟部中央標準局員工消費合作社印製 (請先閲讀背面之注意事項再填寫本頁) (1 〇 )護層 本發明主要為藉由改變氮化鈦層之製程而獲致降低鋁 銅過蝕刻之程度，達到改善金屬步階覆蓋效果以及令孔道 阻抗較為穩定者，可配合參看第一圖所示，為在第一層金 屬位置依序以習知製程形成1500A之鈦層（Ti)以 -5-本紙張尺度適用中國國家標準（CNS ) A4规格（210X297公嫠） 經濟部中央標準局員工消費合作社印製 401462 A7 __B7___ 五、發明説明（屮） 及4000A之鋁銅金屬（A1CU)之後，為令氮化鈦 層（T i N)為以兩步驟實施，亦即在進行氮化鈦沈積之 前幾秒鐘（約1〜5秒鐘）之狀態下，為關閉氮氣氣源， 而僅施加·|氣（50 s c cm)及在較低壓力（1 · 7m To r r)及功率約在6500瓦特之狀態進行沈積作業 ，故而可在前述鋁銅金屬（A 1C u)表面先行形成一質 硬且抗腐蝕之極薄厚度之鈦層（T i)，而第二步驟則為 使用完全相同於習知氮化鈦之沈積方法，亦即為同時施加 有氣氣（1 00 s c cm)及氬氣（50 s c. cm)之環 境下以及在約4mT 〇 r r之壓力以及6 5 0 0瓦特之功 率下，進行約十幾秒鐘之沈積作業，而形成厚度約在2 5 .0A之氮化鈦層（TiN)，而經上述將氮化鈦沈積步驟 為區分為兩步驟實施之下，即在第一圖該下層鋁銅金屬（ A 1 C u )上方位置即形成一以極薄之鈦層（T i )與氮 化鈦層（T i N)合成之構造，而藉由該極薄之鈦層（T i )本身為具有較氮化鈦（T i N)更佳的強度及抗腐蝕 之特性，當可在後續對覆蓋在該氮化鈦（TiN)層上方 及外圍位置之絕縁層（IMD)進行孔道蝕刻步驟以及透 過離子水清洗之步驟時，即藉由該鈦層（T i )之阻擋， 則可降低對下方鋁銅金屬（A 1 C u )之過度蝕刻問題， 而在第一圖中經沈積形成第二金屬層之鈦層（T i )、鋁 銅金屬（AlCu)以及氮化鈦層（TiN)之後，即由 於前述孔道蝕刻步驟時，鋁銅金屬（A 1 C u)損失較小 -6- 本紙張尺度適用中國國家標準（CNS ) A4規格（210X 297公釐） (請先閲讀背面之注意事項再填寫本頁)1T 401462 A7 B7 V. Description of the invention 0) Double-layer structure of titanium layer > In this way, the titanium layer can be used to reduce the degree of peripheral aluminum-copper metal etching. A secondary object of the present invention is to provide a titanium nitride sinking method that can reduce the loss of aluminum and copper during channel etching. The above method can not only avoid excessive loss of aluminum copper, but also make subsequent metals have better steps. Order cover effect and the effect of stabilizing the contact resistance of the channel. In order to allow your reviewers to further understand the method, features and other purposes of the present invention, detailed drawings are attached as follows: (―) · Schematic part: The first figure: is the cross section between two metal layers of the present invention schematic diagram. The second figure is a schematic cross-sectional view between two metal layers. The third step is the channel resistance distribution of each batch of wafers under the titanium nitride process of the present invention. The fourth figure is a distribution diagram of the channel resistance of each batch of wafers under the conventional titanium nitride manufacturing process. (II) Part number: (T i) Titanium layer (A 1 Cu) Aluminum copper metal (TiN) Titanium nitride (IMD) Insulation layer Printed by the Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs (please read the back first) (Please note this page, please fill in this page) (10) Protective layer The present invention is mainly to reduce the degree of aluminum-copper over-etching by changing the process of the titanium nitride layer, to improve the coverage of metal steps and to stabilize the channel impedance. For example, as shown in the first figure, in order to form a 1500A titanium layer (Ti) at the first metal position by a conventional process in order, the paper size of China National Standards (CNS) A4 (210X297) applies to this paper size. Public address) Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs 401462 A7 __B7___ 5. After the description of the invention (及) and the 4000A aluminum-copper metal (A1CU), the titanium nitride layer (T i N) is implemented in two steps. That is, in the state of a few seconds (about 1 to 5 seconds) before the titanium nitride deposition, in order to turn off the nitrogen gas source, only the || gas (50 sc cm) and the lower pressure (1 · 7m To rr) and the power is about 6500 watts for the deposition operation, so An extremely hard and corrosion-resistant titanium layer (T i) is formed on the surface of the aforementioned aluminum copper metal (A 1C u), and the second step is to use the same deposition method as the conventional titanium nitride. That is, under an environment where gas (100 sc cm) and argon (50 s c. Cm) are simultaneously applied, and under a pressure of about 4mT 0rr and a power of 6500 watts, it is performed for about ten seconds. The deposition process of the bell forms a titanium nitride layer (TiN) with a thickness of about 25.0A. After the titanium nitride deposition step is divided into two steps, the lower layer of aluminum and copper is shown in the first picture. Above the metal (A 1 C u), a structure composed of an extremely thin titanium layer (T i) and a titanium nitride layer (T i N) is formed, and by the extremely thin titanium layer (T i) itself In order to have better strength and corrosion resistance than titanium nitride (T i N), when the subsequent etching is performed on the insulating layer (IMD) that covers the titanium nitride (TiN) layer and the surrounding locations In the step and the step of cleaning by ion water, that is, by the blocking of the titanium layer (T i), the excess of the underlying aluminum copper metal (A 1 C u) can be reduced. Etching problem. After the titanium layer (T i), the aluminum copper metal (AlCu), and the titanium nitride layer (TiN) of the second metal layer are formed by depositing in the first figure, the aluminum and copper Small loss of metal (A 1 C u) -6- This paper size applies Chinese National Standard (CNS) A4 specification (210X 297 mm) (Please read the precautions on the back before filling this page)
401462 經濟部中央標準局員工消費合作社印製 A7 B7 五、發明説明（夕） 之故，孔道（VI A)之深度較淺，而該上層鋁銅金屬（ A 1 C u )之填入效果亦較佳（金屬步階覆蓋效果良好） ，更提供可較確實地與下層鋁銅金屬（A 1 C u)相互接 觸，相形之下，該上、下層鋁銅金屬間之接觸阻抗更趨穩 定而不致產生過度漂移者。 而上述可達到穩定接觸阻抗之效果，可配合如第三圖 之本發明氮化鈦製程下之各批號晶片之孔道阻値分佈圖所 示，於第三圖中，每片晶片量五點，共有8 1 8 5個數據 點，此圖顯示各晶片之孔道阻値變化呈標準分佈，幾乎沒 有異常値發生，反觀第四圖之顯示傳統氮化鈦製程下之晶 片孔道阻値分佈圖，每片晶片量五點，共有9 5 8 0個數 據點，此圖顯示異常偏高値較多，而有明顯的漂移現象， 而由第三、四圖相互比較之下，雖兩者之mean値相差不多 ，然第三圖之標準差為〇 · 098，而第四圖則為0 . 2 5 5，由此當可證明本發明較傳統氮化鈦製程有著相當程 度的改善。 而上述本發明製程改變處，為僅將氮化鈦沈積步驟中 之前段為不施加氮氣，而後段為施加氮氣而已，其餘製程 均完全未予更動之情況下，實施上當屬簡便及易於實施， 且可適當地解決孔道蝕刻期間造成鋁銅金屬過度蝕刻所衍 生之金屬步階覆蓋效果降低與孔道阻抗不穩定性之缺點， 確為一具新穎性及可提昇半導體可靠度之氮化鈦形成方法 ，應符專利申請要件，爰依法提出申請。 -7- 本紙張尺度適用中國國家標準（CNS ) A4規格（2丨0X297公釐） (請先閲讀背面之注意事項再填寫本頁)401462 A7 B7 printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs 5. The description of the invention (Evening), the depth of the channel (VI A) is shallow, and the filling effect of the upper aluminum copper metal (A 1 C u) is also Better (the metal step coverage is good), and it can provide more reliable contact with the lower aluminum and copper metal (A 1 Cu). In contrast, the contact resistance between the upper and lower aluminum and copper metal is more stable and stable. Does not cause excessive drift. The above-mentioned effect of achieving stable contact resistance can be matched with the distribution diagram of the channel resistance of each batch of wafers under the titanium nitride process of the present invention shown in the third figure. In the third figure, the amount of each wafer is five points. There are 8 1 8 data points in total. This graph shows that the variation of the channel resistance of each wafer has a standard distribution with almost no abnormal occurrence. In contrast, the fourth graph shows the distribution of the channel resistance of the wafer under the traditional titanium nitride process. The number of wafers is five points, with a total of 9 580 data points. This figure shows that the abnormality is high and there are many drifts, and there is a significant drift phenomenon. From the comparison of the third and fourth figures, the mean phase of the two It is similar, but the standard deviation of the third diagram is 0.098, and the fourth diagram is 0.255, so it can be proved that the present invention has a considerable improvement over the traditional titanium nitride process. Whereas the process of the present invention is changed, only the first stage of the titanium nitride deposition step is not applied with nitrogen, and the latter stage is applied with nitrogen. The rest of the processes are completely unchanged. Implementation is simple and easy. And it can appropriately solve the disadvantages of reducing the step coverage effect and the instability of the channel impedance caused by the over-etching of aluminum and copper metal during the channel etching. It is indeed a novel titanium nitride formation method that can improve the reliability of the semiconductor. , Should comply with the requirements for patent application, and apply in accordance with the law. -7- This paper size applies to Chinese National Standard (CNS) A4 specification (2 丨 0X297 mm) (Please read the precautions on the back before filling this page)
J-------- — — 11 — —.— - ----- III ^ n n — >......I IJ -------- — — 11 — —. —------ III ^ n n — > ...... I I