,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,newnergy9薄膜淀积技术,newnergy9薄膜淀积技术,半导体工艺中所涉及的常用薄膜：,半导体工艺中所涉及的常用薄膜：,最新newnergy9薄膜淀积技术课件,Evaporation(,蒸发）,Evaporation(蒸发）,Sputtering(,溅射）,Sputtering(溅射）,使用加热、等离子体或紫外线等各种能源，使气态物质经化学反应（热解或化学合成）形成固态物质淀积在衬底上的方法，叫做化学汽相淀积,(Chemical Vapor Deposition),技术，简称,CVD,技术。它与真空蒸发和溅射技术并列，是应用较为普遍的一种薄膜淀积技术。,特点：,1,、淀积温度低；,2,、可以淀积各种电学和化学性质都符合要求的薄膜；,3,、均匀性好；,4,、操作简便，适于大量生产；,CVD,技术：,使用加热、等离子体或紫外线等各种能源，使气态物质经化学反应（,CVD,的化学反应大致分为两种类型：,一是一种气态化合物在一定激活能量下被,分解,，生成固态物质淀积在衬底上，而其它则为气态物质跑掉，如：,SiH,4,Si+2H,2,另一类是两种气体化合物经化学,反应,生成新的固态物质和气态物质，如：,3SiH,4,+4NH,3,Si,3,N,4,+12H,2,CVD的化学反应大致分为两种类型：,CVD,的分类：,可按淀积温度，反应腔气压或淀积反应的激活方式分类,低温,CVD(200-500C),中温,CVD,（,500-1000C),高温,CVD,（,1000-1300C),常压,CVD,低压,CVD,热,CVD,等离子体,CVD,光,CVD,等等,CVD的分类：,热,CVD,系统：,热CVD系统：,等离子体,CVD,等离子体CVD,最新newnergy9薄膜淀积技术课件,最新newnergy9薄膜淀积技术课件,Molecular Beam Epitaxy(MBE),分子束外延技术,MBE,自,1960,年开始就有人提出，是一种超精密和极精确的薄膜生长技术。其利用的是蒸发原理，将分子束射至单晶衬底上生长单晶外延层的方法。,Molecular Beam Epitaxy(MBE)MB,MBE,的特点：,超高真空；设备中外延生长室真空度可达,5x10,-11,Torr,这样分子平均自由程,L,较大。例如：,P=10,-9,Torr,L=5x10,6,cm,。这样大的自由程使分子碰撞几率很小，薄膜生长均匀，生长速率和组分可精确控制。,可以实现低温过程；这样能减少杂质扩散和沾污的几率。利用,MBE,技术可生长出位错密度,10,2,cm,-2,的外延层。,原位监控；,MBE,设备上安装有许多原位监控仪器，可以实时监控外延薄膜的生长参数以及物理性能。,(UHV=Ultra High Vacuum),MBE的特点：,Photolithography,Lithography is the process in which a microelectronics patterns are transfer to a substrate.This transfer can be aided by light,electron-beams,ion beams,x-rays,etc.,Without the techniques of pattern definition,the fabrication of multiple devices on one semiconductor would be impossible.,Although the techniques of pattern definition seem simple they are the,heart,of modern IC fabrication,.,半导体器件制作,Photolithography半导体器件制作,Photoresist,Photo lithography is a process in which wafer is coated with a light sensitive polymer called photoresist.Polyisoprene is an example of a commonly used photoactive agent.,A mask is used to expose selected areas of photoresist to UV light.The UV light induces polymerization in the exposed photoresist.UV causes it to cross link rendering it insoluble in developing solution.Such a photoresist is called a positive photoresist.A negative photoresist shows an opposite behavior.That is exposure to UV makes the photoresist soluble in developing solution.,Photoresist,!Remember,:,There are two types of photoresist:,*NEGATIVE-unexposed areas removed,*POSITIVE-exposed areas removed,Negative resist is the most often used because it is less affected by etchants although positive resist offers better resolution.,Positive resists are more capable of producing the small size of modern device features which are typically below 1.0 m but may be as small as 0.15 m.,!Remember:There are two type,光刻的大致工艺流程：,涂胶：一般从高温炉中,取出硅片立即涂胶或在,180-,200C,恒温干燥箱中烘烤,30,分钟后再进行涂胶。要,求粘附性能良好，厚度均,匀适当。,前烘：在,80 C,恒温干燥箱中烘,10-15,分钟。目,的是使胶膜体内溶剂充分挥发，使胶膜干燥，以,增强胶膜与,SiO2,膜的粘附性和胶膜的耐磨,光刻的大致工艺流程：,曝光与显影：在涂好光刻胶的硅片表面覆盖掩膜版,(Mask),，一般利用紫外光进行选择性照射，使光照部分光刻胶发生光化学反应，经显影将部分光刻胶除去得到相应的图形。,曝光与显影：在涂好光刻胶的硅片表面覆盖掩膜版(Mask)，一,坚膜：一般将显影后的硅片放在烘箱中热烘,30,分钟左右使经显影时软化、膨胀的胶膜坚固。这样可使胶膜与硅片贴得更牢，同时也增强了胶膜本身的抗蚀能力。,腐蚀：在用正胶的情况下，利用适当的腐蚀液将,SiO,2,或,Al,腐蚀掉，而有光刻胶覆盖的区域保存下来。,去胶：腐蚀结束后，利用湿法去胶，氧气去胶或等离子体去胶等方法将覆盖在硅片表面的保护胶膜去除。,坚膜：一般将显影后的硅片放在烘箱中热烘30分钟左右使经显影时,最新newnergy9薄膜淀积技术课件,Exposure Method:,*CONTACT PRINTING-1x mask required,；,*,DIRECT STEP-5x mask required,；,*,E-BEAM-no mask required,；,Exposure Method:,最新newnergy9薄膜淀积技术课件,最新newnergy9薄膜淀积技术课件,最新newnergy9薄膜淀积技术课件,最新newnergy9薄膜淀积技术课件,X-Ray Lithography,X-Ray lithography(XRL)consists of proximity printing,of a mask onto a wafer.,Advantages,1)resolution and process simplicity(linewidth1 m),2)no need for multilevel resist systems used in e-beam,lithography,3)XRL parallel writing process,e-beam is a serial.,X-Ray Lithography,Etch,Process that follows immediately after photolithography step is the removal of material from areas unprotected by photoresist.This process must be selective;that is SiO,2,is removed while leaving photoresist and silicon intact.It must also be anisotropic;that is etching should be in one direction only.,Etch,Etch Method:,Two types of etching processes are used in practice;namely,chemical and physical etching.In purely chemical etching material is removed by dissolution which is highly selective but not anisotropic.In purely physical method material is removed by bombardment of high energy ions which is inherently anisotropic but unselective.,As an example,SiO,2,which is used as a mask for drive in diffusion is removed by exposure to hydrogen fluoride.Hydrogen fluoride reacts with SiO,2,to form volatile SiF,4,which is swept away by inert argon gas.,Etch Method:Two types of etchi,湿法刻蚀特点：,选择性高；,生产量大；加工精度：,3m,装置成本低；,湿法刻蚀特点：,干法刻蚀特点,:,可控性好；,加工精度高,可达,0.2m,；,可加工设计形状；,干法刻蚀特点:,最新newnergy9薄膜淀积技术课件,对于硅系材料,最常用的是用在,CF,4,中放电所产生的,等离子体来腐蚀,Si,、多晶硅和,Si,3,N,4,。,主要反应,：,在刻蚀过程中起主要作用的是原子态,F,和,CF,3,游离基。近来人们发现在,CF,4,中添加少量氧可使,Si,的腐蚀速率明显提高。这是因为,O,2,与等离子体中的,CF,3,、