3.155J/6.152 J Fall2003 MOSCAP 3. Dry-etch polysilicon in He/Cl2 plasma Use the LAM490B to etch exposed gate polysilicon that is not protected by photoresist Use recipe"POLY EP", This recipe feautres automatic endpoint detection From the etch time, calculate the average etch rate. Inspect wafers visually with optical microscope 4. Strip photoresist with the Matrix System One Stripper(Asher Pre-lab questions 1. Describe the various alignment marks on the reticle 2. Explain the difference between isotropic and anisotropic etch characteristics 3. What chemical is used to etch the polysilicon? Is this an isotropic or anisotropic etch? 4. Sketch the cross-section taken through the gate of a device MOSCAP Testing Location: ICL, EML (5 floor, Building 39) Overview of lab session: This lab session will take place in the Exploratory Materials Laboratory(EML). Electrical testing will be performed to characterize materials and device performance Lab object Introduce electrical testing instruments and procedures Characterize device performance and materials Relate device characteristics to fabrication process Lab procedures: 1. Device Characterization: MOS Capacitor The following devices will be measured 1)500 X 500 um cap, with anneal 2)200 X 200 um" cap, with anneal Follow instructions(in SOP for test station for use of HP-4061A system to perform C-V measurement(see appendix)on MOS capacitor. The gate electrode is probed, along with the backside of the substrate At high frequency(100 kHz), the result should be similar to this cv curve for an aluminum gate MOS structure3.155J / 6.152J Fall 2003 MOSCAP 7 3. Dry-etch polysilicon in He/Cl2 plasma. • Use the LAM490B to etch exposed gate polysilicon that is not protected by photoresist. Use recipe "POLY EP".; This recipe feautres automatic endpoint detection. From the etch time, calculate the average etch rate. • Inspect wafers visually with optical microscope. 4. Strip photoresist with the Matrix System One Stripper (Asher) Pre-lab questions: 1. Describe the various alignment marks on the reticle. 2. Explain the difference between isotropic and anisotropic etch characteristics. 3. What chemical is used to etch the polysilicon? Is this an isotropic or anisotropic etch? 4. Sketch the cross-section taken through the gate of a device. MOSCAP Testing Location: ICL, EML (5nd floor, Building 39) Overview of Lab Session: This lab session will take place in the Exploratory Materials Laboratory (EML). Electrical testing will be performed to characterize materials and device performance. Lab Objectives: • Introduce electrical testing instruments and procedures • Characterize device performance and materials • Relate device characteristics to fabrication process Lab Procedures: 1. Device Characterization: MOS Capacitor The following devices will be measured: 1) 500 x 500 µm2 cap, with anneal 2) 200 x 200 µm2 cap, with anneal Follow instructions (in SOP for test station ) for use of HP-4061A system to perform C-V measurement (see appendix) on MOS capacitor. The gate electrode is probed, along with the backside of the substrate. At high frequency (100 kHz), the result should be similar to this CV curve for an aluminum gate MOS structure