本文選題：低k介質(zhì)　切入點：化學機械拋光　出處：《河北工業(yè)大學》2015年碩士論文　論文類型：學位論文

【摘要】：隨著集成電路產(chǎn)業(yè)的不斷發(fā)展,銅互連特征尺寸不斷降低,布線層數(shù)不斷增加,互連引線延遲(RC延遲)成為不可忽視的制約集成電路發(fā)展的一大障礙。因此銅、鉭、低k介質(zhì)等材料被引入到集成電路制造工藝中。伴隨新材料的引入,傳統(tǒng)刻蝕工藝已經(jīng)不能滿足生產(chǎn)要求,大馬士革工藝應運而生。大馬士革工藝中,材料平坦化采用化學機械拋光(CMP)的方法。阻擋層的化學機械拋光能夠最終決定平坦化效果和集成電路成品率。阻擋層拋光中,低k材料疏松多孔,相對介電常數(shù)容易受到CMP工藝影響而升高,影響器件性能和可靠性。因此阻擋層拋光既要實現(xiàn)較高的材料去除速率、保證工藝過程對碟形坑有明顯的修正效果,又要保證工藝過程對低k材料的相對介電常數(shù)影響較小。低k材料是阻擋層的一部分,本課題首先對阻擋層拋光中的速率選擇性進行了深入研究。通過大量單因素實驗研究了堿性拋光液的磨料、螯合劑、活性劑、pH對Cu/Ta/SiO2/SiOCH拋光的作用效果,初步研發(fā)了一種堿性拋光液,并在12英寸單層圖行片上驗證了使用堿性拋光液進行阻擋層拋光的可行性。課題進行了低k材料CMP的研究。本文在研究相對介電常數(shù)概念的基礎(chǔ)上,闡述了通過電容測量相對介電常數(shù)的理論基礎(chǔ)。通過紅外光譜儀觀察了CMP前后傅里葉紅外光譜圖變化情況,發(fā)現(xiàn)CMP使材料內(nèi)的化學物質(zhì)發(fā)生了一定變化。在此基礎(chǔ)上,進一步研究了不同磨料濃度和拋光液pH值對相對介電常數(shù)的影響情況,發(fā)現(xiàn)低磨料或低pH的堿性拋光液對材料介電常數(shù)影響更小,另外通過拋光后的退火處理也可以進一步修正材料k值。文章最后采用降低拋光液pH值的方法改進了初步研發(fā)的堿性阻擋層拋光液。改進后的堿性阻擋層拋光液可以把碟形坑和蝕坑控制在可接受范圍內(nèi),并且使圖形片電阻值可以控制在1.19kohm至1.46kohm,互連電容為2.24~2.43pF,漏電流極小,滿足工業(yè)要求,取得了良好的拋光效果。本課題通過一系列研究,使改進后的堿性拋光液對低k介質(zhì)材料k值的影響可以與主流的酸性拋光液相當,并且在其他性能上取得優(yōu)良效果。這種拋光液成分簡單、便于后續(xù)清洗、速率選擇好、對設(shè)備腐蝕小、環(huán)境污染小。
[Abstract]:With the continuous development of the integrated circuit industry, copper interconnect feature size decreases, the wiring layers increasing, interconnection leads delay (RC delay) has become a major obstacle to the development of integrated circuit can not be ignored. Therefore, copper, tantalum, low k dielectric material manufacturing technology was introduced into the integrated circuit. With the introduction of new materials the traditional etching process has been unable to meet the requirements of production process, Damascus Damascus came into being. In the process of flattening materials with chemical mechanical polishing (CMP) method. The chemical mechanical polishing barrier layer can be decided flattening effect and IC yield. Barrier polishing, low k material is porous, relative dielectric constant CMP process vulnerable to the effects of increased, affecting the performance and reliability of devices. Therefore barrier polishing to achieve both high material removal rate, to ensure the process of dish shaped pit There is an obvious compensation effect, but also to ensure the process of low k material relative permittivity is less affected. Low k material is a part of the barrier layer, this paper conducts an in-depth study on the blocking rate of selective layer polishing. Through a single factor experiment of alkaline polishing abrasive, chelating agent. The effect of surfactant, pH Cu/Ta/SiO2/SiOCH polishing, developed an alkaline polishing liquid, and verifies the feasibility of the barrier layer polishing using alkaline slurry in a 12 inch single map sheet. Research of low k material CMP. Based on the research of the relative dielectric constant on the concept describes the theoretical basis of the relative dielectric constant of capacitance measurement. Changes of FTIR spectrums before and after CMP were observed by infrared spectroscopy, the results showed that CMP chemical substances within the material changed. On this basis, further research on the effects of abrasive concentration and slurry pH value effect on the relative dielectric constant, low abrasive or low pH alkaline slurry of the dielectric constant effect is smaller, also by annealing after polishing can be further modified material K value. Finally the basic preliminary improvement research methods to reduce the pH value of slurry of barrier slurry. The improved alkaline barrier slurry can be controlled in an acceptable range of dishing and erosion pits, and the graphics sheet resistance can be controlled in 1.19kohm to 1.46kohm, 2.24~2.43pF interconnect capacitance, small leakage current and meet the requirement of industry, achieve the polishing effect is good. This topic through a series of studies, the effect of alkaline slurry after the improvement of low k dielectric material K value is equal to the acidic polishing liquid and other properties in the mainstream, The polishing liquid has the advantages of simple composition, easy cleaning, good selection of speed, small corrosion to equipment and small environmental pollution.

【學位授予單位】：河北工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN305.2

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本文編號：1610961