Thin Film Deposition Three main Types of cvD: APCVD Atmospheric Pressure CVD No vacuum system is required Fast deposition, but poor step coverage and defect problems In-Line Continuous Belt furnace design Single head, controlled flow Assembly Purge Plc Watkins-Johnson zhang@fudan.edu.cn复旦大学张荣君
rjzhang@fudan.edu.cn 复旦大学 张荣君 Thin Film Deposition • Three Main Types of CVD: APCVD – Atmospheric Pressure CVD – No vacuum system is required. – Fast deposition, but poor step coverage and defect problems
Thin Film Deposition Three Main Types of CVD: LPCVD Low Pressure CvD, so a vacuum system is required Excellent purity, uniformity, and step coverage Requires higher temperatures Reactive Gas Inlet Heating element Cantilever o Vacuum Pump zhang@fudan.edu.cn复旦大学张荣君
rjzhang@fudan.edu.cn 复旦大学 张荣君 Thin Film Deposition • Three Main Types of CVD: LPCVD – Low Pressure CVD, so a vacuum system is required. – Excellent purity, uniformity, and step coverage. – Requires higher temperatures. Heating Element Cantilever Reactive Gas Inlet To Vacuum Pump
Thin Film Deposition Three Main Types of CVD: PECVD(Plasma Enhanced LPCVD with RF hardware to generate a plasma Plasma energy enhances the chemical reaction to achieve very low temperature deposition and fast deposition rates(up to 40X faster) PECVD IS exactly the same as plasma etching except that the Plasma products are solid instead of volatile (gas) Gas口 zhang@fudan.edu.cn复旦大学张荣君
rjzhang@fudan.edu.cn 复旦大学 张荣君 Thin Film Deposition • Three Main Types of CVD: PECVD (Plasma Enhanced) – LPCVD with RF hardware to generate a plasma – Plasma energy enhances the chemical reaction to achieve very low temperature deposition and fast deposition rates (up to 40X faster) • PECVD is exactly the same as plasma etching except that the products are solid instead of volatile (gas)
Thin Film Deposition Densification(or reflow): Used to smoothe and densify some cvd films following deposition Applies to doped oxides boron and phosphorous are used to reduce reflow temperature of the film Densifies film Rounds sharp corners to improve step coverage Performed in a diffusion furnace or an rTP system Simultaneous deposition Etch, Deposition high-aspect-ratio gaps will be subject to "bread-loafing effect first deposition partially fills hole sputter etch step bevels edges at gap entrance final deposition completes filling of the hole without a gap zhang@fudan.edu.cn复旦大学张荣君
rjzhang@fudan.edu.cn 复旦大学 张荣君 Thin Film Deposition • Densification (or reflow): – Used to smoothe and densify some CVD films following deposition. – Applies to doped oxides (Boron and Phosphorous are used to reduce reflow temperature of the film) – Densifies film – Rounds sharp corners to improve step coverage – Performed in a diffusion furnace or an RTP system. • Simultaneous Deposition, Etch, Deposition – high-aspect-ratio gaps will be subject to “bread-loafing” effect – first deposition partially fills hole – sputter etch step bevels edges at gap entrance – final deposition completes filling of the hole without a gap
CVD的基本原理 1热分解反应沉积 最简单的沉积反应:反应气体源物质在高温下发生热分解,沉 积到加热的基片上成膜。可以制备金属、半导体以及绝缘介质 薄膜等。如: SiH4600800Si+2H, 2Al(OC3H,)3 420C AL203+6C3H6+3H,0 2还原反应沉积 些金属和半导体的卤化物,通以氢气,可以还原出相应元素 的薄膜,这是制备高纯度金属膜和半导体纯硅的基本方法 如: SicL+2 H 1150-1200'C Si+4HCI zhang@fudan.edu.cn复旦大学张荣君
rjzhang@fudan.edu.cn 复旦大学 张荣君 CVD的基本原理 2 还原反应沉积 一些金属和半导体的卤化物，通以氢气，可以还原出相应元素 的薄膜，这是制备高纯度金属膜和半导体纯硅的基本方法。 如： SiCl4+2 H2 1150~1200℃ Si+4HCl 1 热分解反应沉积. 最简单的沉积反应：反应气体源物质在高温下发生热分解，沉 积到加热的基片上成膜。可以制备金属、半导体以及绝缘介质 薄膜等。如： SiH4 600~800℃ Si+2H2 2Al(OC3H7)3 420℃ Al2O3+6C3H6+3H2O