TWI426125B

TWI426125B - Cleaning solution and application thereof

Info

Publication number: TWI426125B
Application number: TW96143815A
Authority: TW
Inventors: Judy Jianfen Jing; Andy Chunxiao Yang
Original assignee: Anji Microelectronics Co Ltd
Priority date: 2007-11-20
Filing date: 2007-11-20
Publication date: 2014-02-11
Also published as: TW200923079A

Description

清洗液及其應用 Cleaning fluid and its application

本發明係關於一種清洗液及其在化學機械拋光後晶片清洗之應用。 This invention relates to a cleaning fluid and its use in wafer cleaning after chemical mechanical polishing.

在半導體製程中，化學機械拋光(CMP)之方式時常被用以使晶片之表面平整化。在研磨漿料並拋光晶片之後，在晶片表面會產生許多殘留物，例如研磨顆粒、研磨漿料中的化學成分及拋光漿料的反應生成物。這些殘留的污染物必須在進入到下一個半導體製程之步驟前被清洗乾淨，否則將會嚴重影響後續之製程以及晶片的可靠度。所以通常在晶片經過CMP研磨後，都會使用一種清洗液來清洗晶片表面。 In semiconductor processes, chemical mechanical polishing (CMP) is often used to planarize the surface of the wafer. After the slurry is polished and the wafer is polished, a number of residues are generated on the surface of the wafer, such as abrasive particles, chemical components in the abrasive slurry, and reaction products of the polishing slurry. These residual contaminants must be cleaned before entering the next semiconductor process, otherwise the subsequent process and wafer reliability will be severely affected. Therefore, usually after the wafer is CMP-polished, a cleaning solution is used to clean the surface of the wafer.

傳統上所使用之CMP研磨後清洗液大多是基於氨水之鹼性溶液。例如在專利文獻TW494020B中所揭露之一種應用於多晶矽CMP研磨後的清洗液，即是在已稀釋的鹼性氨水溶液中加入表面活性劑及螯合劑。藉此，該清洗液用以去除在多晶矽表面所殘留之研磨顆粒和金屬離子。然而，該清洗液中所使用的氨水等有機氨之氣味難聞，易造成環境污染。 The CMP post-cleaning solution conventionally used is mostly an alkaline solution based on ammonia. For example, one of the solutions disclosed in the patent document TW494020B is applied to a cleaning solution after polycrystalline CMP polishing, that is, a surfactant and a chelating agent are added to a diluted alkaline aqueous ammonia solution. Thereby, the cleaning liquid is used to remove abrasive particles and metal ions remaining on the surface of the polycrystalline silicon. However, the smell of organic ammonia such as ammonia water used in the cleaning liquid is unpleasant, and it is likely to cause environmental pollution.

因此，本發明提出一種應用於化學機械拋光後晶片清洗之清洗液，以解決上述問題。 Therefore, the present invention proposes a cleaning liquid applied to wafer cleaning after chemical mechanical polishing to solve the above problems.

本發明之目的是為了解決上述問題，而提供一種清洗液。 The object of the present invention is to solve the above problems and to provide a cleaning liquid.

本發明提出之清洗液，含有至少一氧化劑、至少一胍類化合物和水。 The cleaning solution of the present invention contains at least one oxidizing agent, at least one hydrazine compound and water.

在本發明中，胍類化合物係具有去除殘餘研磨顆粒之作用。在所有的胍類化合物中，較佳的選擇有：胍、碳酸胍、乙酸胍、磷酸氫二胍、鹽酸胍、硝酸胍、硫酸胍、氨基胍、氨基胍碳酸氫鹽、氨基胍磺酸鹽、氨基胍鹽酸或氨基胍硝酸鹽等。至於胍類化合物的較佳含量為質量百分比0.01-10%。 In the present invention, the quinone compound has the effect of removing residual abrasive particles. Among all terpenoids, preferred choices are: barium, strontium carbonate, and Barium acid, dihydrogen phosphate, barium hydrochloride, barium nitrate, barium sulfate, aminoguanidine, aminoguanidine hydrogencarbonate, aminoguanidinesulfonate, aminoguanidine hydrochloride or aminoguanidine nitrate. The preferred content of the terpenoid is 0.01-10% by mass.

在本發明中，氧化劑之較佳選擇為過氧化氫、過氧化脲、過氧甲酸或過氧乙酸。至於氧化劑之較佳含量為質量百分比0.1-10%。 In the present invention, the preferred choice of oxidizing agent is hydrogen peroxide, urea peroxide, peroxyformic acid or peracetic acid. The preferred content of the oxidizing agent is 0.1 to 10% by mass.

在本發明中，清洗液之pH值可以介於pH 7-pH 12，而較佳之範圍則是在pH 8-pH 11之間。在實際應用中，可視需要採用無機酸等常規pH調節劑來調節該清洗液至所需的pH值。 In the present invention, the pH of the cleaning solution may range from pH 7 to pH 12, and preferably ranges from pH 8 to pH 11. In practical applications, a conventional pH adjusting agent such as a mineral acid may be used to adjust the cleaning liquid to a desired pH value.

根據本發明之清洗液，在製備時先加入水和胍類化合物後，加以攪拌均勻，並視需要採用無機酸等常規pH調節劑調節清洗液至所需的pH值。該清洗液在使用之前只需加入氧化劑混合均勻即可。 According to the cleaning liquid of the present invention, water and an anthraquinone compound are added at the time of preparation, and the mixture is uniformly stirred, and a conventional pH adjusting agent such as a mineral acid is used to adjust the cleaning liquid to a desired pH value as needed. The cleaning solution can be mixed evenly by adding an oxidizing agent before use.

本發明之另一目的在於將該清洗液應用於經過化學機械拋光後之晶片清洗過程。該晶片之種類可以是多晶矽、單晶矽、二氧化矽等非金屬晶片。 Another object of the present invention is to apply the cleaning solution to a wafer cleaning process after chemical mechanical polishing. The type of the wafer may be a non-metal wafer such as polycrystalline germanium, single crystal germanium or germanium dioxide.

本發明所提出之清洗液可去除在經過化學機械拋光後之晶片表面上所殘留之研磨顆粒及化學物質。並且由於該清洗液之金屬離子含量低且無氣味，因此可以減少金屬離子所造成之污染。 The cleaning solution proposed by the present invention can remove abrasive particles and chemicals remaining on the surface of the wafer after chemical mechanical polishing. Moreover, since the cleaning liquid has a low metal ion content and is odorless, contamination by metal ions can be reduced.

關於本發明之優點與精神可以藉由以下的發明詳述得到進一步的瞭解。 The advantages and spirit of the present invention will be further understood from the following detailed description of the invention.

下面通過實施例的方式進一步說明本發明，但是並不因此將本發明限制在下列所述的實施例範圍之中。 The invention is further illustrated by the following examples, but is not intended to limit the invention to the scope of the embodiments described below.

實施例1~13Examples 1 to 13

表1顯示了用於清洗液實施例1~13的配方，水為餘量。按表中所給各成分及其含量，先加入水和胍類化合物，並加以攪拌均勻，之後採用硫酸調節到使用者所需要的pH值，使用前只需在該清洗液加入氧化劑混合均勻即可。 Table 1 shows the formulations used in the cleaning solutions of Examples 1 to 13, with water being the balance. According to the ingredients and their contents in the table, first add water and terpenoids, and stir them evenly. Then adjust the pH to the user's pH with sulfuric acid. Just add the oxidizing agent to the cleaning solution before use. can.

效果實施例1Effect Example 1

分別採用去離子水和實施例3的清洗液，對於經過化學機械拋光後的多晶矽晶片表面進行刷洗。在本實施例中，使用的滾刷為聚乙烯醇(PVA)滾刷，刷洗時間為1min，滾刷轉速為100rpm，清洗液流量為500ml/min。用去離子水清洗後的晶片表面，如圖1和2所示；用清洗液清洗後的晶片表面，如圖3所示。 The surface of the polycrystalline germanium wafer after chemical mechanical polishing was brushed using deionized water and the cleaning solution of Example 3, respectively. In the present embodiment, the roller brush used was a polyvinyl alcohol (PVA) roller brush, the brushing time was 1 min, the roller brush rotation speed was 100 rpm, and the cleaning liquid flow rate was 500 ml/min. The surface of the wafer after washing with deionized water, as shown in Figures 1 and 2; the surface of the wafer after cleaning with a cleaning solution, as shown in Figure 3.

如圖1至圖3所示，根據本發明之清洗液對於多晶矽晶片拋光後表面所殘留之研磨顆粒及化學物質具有良好的清洗能力。而且在清洗過程中，該清洗液之金屬離子含量低且無氣味，因此可以減少金屬離子所造成之污染。 As shown in FIG. 1 to FIG. 3, the cleaning liquid according to the present invention has good cleaning performance for abrasive particles and chemicals remaining on the surface of the polycrystalline silicon wafer after polishing. force. Moreover, during the cleaning process, the cleaning liquid has a low metal ion content and is odorless, so that the contamination caused by the metal ions can be reduced.

效果實施例2Effect Example 2

分別採用去離子水和實施例7的清洗液，對經過化學機械拋光後的二氧化矽晶片表面進行刷洗，在此實施例中，所使用的滾刷為聚乙烯醇(PVA)滾刷，刷洗時間1min，滾刷轉速為100rpm，清洗液流量為500ml/min。用去離子水清洗後的晶片表面，如圖4所示。用清洗液清洗後的晶片表面，如圖5所示。 The surface of the cerium oxide wafer after chemical mechanical polishing was brushed with deionized water and the cleaning liquid of Example 7, respectively. In this embodiment, the roller brush used was a polyvinyl alcohol (PVA) roller brush, brushed. The time was 1 min, the rolling brush speed was 100 rpm, and the cleaning liquid flow rate was 500 ml/min. The surface of the wafer after washing with deionized water is shown in FIG. The surface of the wafer after cleaning with a cleaning solution is shown in FIG.

如圖4及圖5所示，根據本發明之清洗液對於二氧化矽晶片經過拋光後在表面所殘留之研磨顆粒和化學物質具有良好的清洗能力。而且在清洗過程中，根據本發明之清洗液的金屬離子含量低且無氣味，因此可以減少金屬離子所造成之污染。 As shown in FIGS. 4 and 5, the cleaning liquid according to the present invention has a good cleaning ability for the abrasive particles and chemicals remaining on the surface of the ceria wafer after polishing. Moreover, in the cleaning process, the cleaning liquid according to the present invention has a low metal ion content and is odorless, so that contamination by metal ions can be reduced.

效果實施例3Effect Example 3

分別採用去離子水和實施例9的清洗液，對有多晶矽/二氧化矽圖案的晶片經過化學機械拋光後的表面進行刷洗，在本實施例中，使用的滾刷為聚乙烯醇(PVA)滾刷，刷洗時間1min，滾刷轉速為100rpm，清洗液流量為500ml/min。用去離子水清洗後的晶片表面，如圖6所示，用清洗液清洗後的晶片表面，如圖7所示。 The surface of the wafer having the polycrystalline germanium/cerium oxide pattern was subjected to chemical mechanical polishing using deionized water and the cleaning liquid of Example 9, respectively. In the present embodiment, the roller brush used was polyvinyl alcohol (PVA). Rolling brush, brushing time 1 min, roller brush speed 100 rpm, cleaning fluid flow rate 500 ml / min. The surface of the wafer after washing with deionized water, as shown in Fig. 6, was cleaned with a cleaning liquid, as shown in Fig. 7.

如圖6和7所示，根據本發明之清洗液對於多晶矽/二氧化矽晶片經過拋光後之表面上所殘留的研磨顆粒和化學物質具有良好的清洗能力。而且在清洗過程中，根據本發明的清洗液之金屬離子含量低且無氣味，因此可以減少金屬離子所造成之污染。 As shown in Figures 6 and 7, the cleaning solution according to the present invention has a good cleaning ability for the abrasive particles and chemicals remaining on the polished surface of the polysilicon/cerium oxide wafer. Moreover, in the cleaning process, the cleaning liquid according to the present invention has a low metal ion content and is odorless, so that contamination by metal ions can be reduced.

本發明所使用的原料和試劑均是市售所得。 The starting materials and reagents used in the present invention are all commercially available.

藉由以上較佳具體實施例之詳述，係希望能更加清楚描述本發明之特徵與精神，而並非以上述所揭露的較佳具體實施例來對本發明之範疇加以限制。相反地，其目的是希望能涵蓋各種改變及具相等性的安排於本發明所欲申請之專利範圍的範疇內。因此，本發明所申請之專利範圍的範疇應該根據上述的說明作最寬廣的解釋，以致使其涵蓋所有可能的改變以及具相等性的安排。 The features and spirit of the present invention are more clearly described in the above detailed description of the preferred embodiments, and the preferred embodiments disclosed herein The scope of the invention is limited. On the contrary, the intention is to cover various modifications and equivalents within the scope of the invention as claimed. Therefore, the scope of the patented scope of the invention should be construed as broadly construed in the

圖一為使用去離子水清洗後的多晶矽晶片表面的SEM圖，其中之白色斑點為晶片表面殘留的研磨顆粒。 Figure 1 is an SEM image of the surface of a polycrystalline silicon wafer after cleaning with deionized water, where the white spots are abrasive particles remaining on the surface of the wafer.

圖二為使用去離子水清洗後的多晶矽晶片表面的SEM圖，其中之白色斑跡為晶片表面殘留的化學物質。 Figure 2 is an SEM image of the surface of a polycrystalline silicon wafer after cleaning with deionized water, where the white stains are chemicals remaining on the surface of the wafer.

圖三為使用實施例3的清洗液清洗之後多晶矽晶片表面的SEM圖。 Figure 3 is an SEM image of the surface of a polycrystalline silicon wafer after cleaning using the cleaning solution of Example 3.

圖四為使用去離子水清洗後的二氧化矽晶片表面的SEM圖，其中之白色斑點為晶片表面殘留物。 Figure 4 is an SEM image of the surface of a ceria wafer after cleaning with deionized water, where the white spots are wafer surface residues.

圖五為使用實施例7的清洗液清洗後的二氧化矽晶片表面的SEM圖。 Figure 5 is an SEM image of the surface of a ceria wafer after cleaning using the cleaning solution of Example 7.

圖六為使用去離子水清洗後的有圖案的多晶矽/二氧化矽晶片表面的SEM圖，其中之斑點為晶片表面殘留物。 Figure 6 is an SEM image of the surface of a patterned polysilicon/cerium oxide wafer after cleaning with deionized water, where the spots are wafer surface residues.

圖七為使用實施例9的清洗液清洗後的有圖案的多晶矽/二氧化矽晶片表面之SEM圖。 Figure 7 is an SEM image of the surface of a patterned polycrystalline germanium/cerium oxide wafer after cleaning using the cleaning solution of Example 9.

Claims

一種清洗液，包含至少一氧化劑、至少一胍類化合物及水，其中該胍類化合物為胍、碳酸胍、乙酸胍、磷酸氫二胍、鹽酸胍、硝酸胍、硫酸胍、氨基胍、氨基胍碳酸氫鹽、氨基胍磺酸鹽、氨基胍鹽酸鹽或氨基胍硝酸鹽，該氧化劑為過氧化氫、過氧化脲、過氧甲酸或過氧乙酸，該清洗液的pH值為7-12，其中該胍類化合物之含量為質量百分比0.01-10%，其中該氧化劑之含量為質量百分比0.1-10%。 A cleaning solution comprising at least one oxidizing agent, at least one hydrazine compound and water, wherein the hydrazine compound is cerium, cerium carbonate, cerium acetate, cerium hydrogen phosphate, cerium hydrochloride, cerium nitrate, cerium sulfate, amino guanidine, aminoguanidine a hydrogencarbonate, an aminoguanidine sulfonate, an aminoguanidine hydrochloride or an aminoguanidine nitrate, the oxidant being hydrogen peroxide, urea peroxide, peroxyformic acid or peracetic acid, the pH of the cleaning solution being 7-12 Wherein the content of the anthraquinone compound is 0.01-10% by mass, wherein the content of the oxidizing agent is 0.1-10% by mass.

如申請專利範圍第1項所述之清洗液，其中該清洗液的pH值為8-11。 The cleaning solution of claim 1, wherein the cleaning solution has a pH of 8-11.

如申請專利範圍第1項所述之清洗液，該清洗液係應用於化學機械拋光後之晶片清洗。 For example, the cleaning liquid described in claim 1 is applied to wafer cleaning after chemical mechanical polishing.