Plasma Charging Damage

In the 50 years since the invention of transistor, silicon integrated circuit (IC) technology has made astonishing advances. A key factor that makes these advances possible is the ability to have precise control on material properties and physical dimensions. The introduction of plasma processing in pattern transfer and in thin film deposition is a critical enabling advance among other things. In state of the art silicon Ie manufacturing process, plasma is used in more than 20 different critical steps. Plasma is sometimes called the fourth state of matter (other than gas, liquid and solid). It is a mixture of ions (positive and negative), electrons and neutrals in a quasi-neutral gaseous steady state very far from equilibrium, sustained by an energy source that balances the loss of charged particles. It is a very harsh environment for the delicate ICs. Highly energetic particles such as ions, electrons and photons bombard the surface of the wafer continuously. These bombardments can cause all kinds of damage to the silicon devices that make up the integrated circuits.

Table of Contents:
1. Thin Gate-oxide Wear-out and Breakdown.- 1.1 The MOSFET.- 1.2 Tunneling Phenomena in Thin Oxide.- 1.3 Thin Oxide Breakdown Measurements.- 1.4 Gate-oxide Breakdown Models.- 1.5 Trap Generation Model and Acceleration Factors.- 1.6 Defects, Traps and Latent Defects.- References.- 2. Mechanism of Plasma Charging Damage I.- 2.1 Basic Plasma Characteristics.- 2.2 Charge Balance and Plasma Charging.- 2.3 Charging in the Presence of an Applied Bias.- 2.4 Fowler-Nordheim (FN) Tunneling and Charge Balance.- 2.5 Antenna Effect.- 2.6 Uniformity of Electron Temperature.- 2.7 Charging Damage by High-density Plasma.- References.- 3. Mechanism of Plasma Charging Damage II.- 3.1 Electron-shading Effect.- 3.2 AC Charging Effect.- 3.3 RF Bias Transient Charging Damage.- References.- 4. Mechanism of Plasma Charging Damage III.- 4.1 Plasma Charging Damage from Dielectric Deposition.- 4.2 Plasma Charging Damage from Magnetized Plasma.- 4.3 Plasma Charging Damage at the Transistor Channel’s Edge.- 4.4 Plasma Charging Damage in Very Short Range.- 4.5 Hidden Antenna Effects.- References.- 5. Charging Damage Measurement I ¡ª Determination of Plasma’s Ability to Cause Damage.- 5.1 Direct Plasma Property Measurement with Langmuir Probe.- 5.2 Stanford Plasma-On-Wafer Real-Time (SPORT) Probe.- 5.3 Using MNOS Device to Measure Plasma Charging Voltage.- 5.4 EEPROM and CHARM®.- 5.5 Common Problems with Methods that Measure Plasma Properties Directly.- 5.6 Rapid In-line Charge Sensing Methods.- References.- 6. Charging Damage Measurement II ¡ª Direct Measurement of Damage.- 6.1 Measurement Challenge.- 6.2 Test Devices.- 6.3 Breakdown Tests.- 6.4 Wear-out Tests.- References.- 7. Coping with Plasma Charging Damage.- 7.1 Impact of Plasma Charging Damage on Yield and Reliability.- 7.2 Fixing theDamaging Process.- 7.3 Use of Design Rules.- 7.4 Diode Protection.- 7.5 Failure Criteria Problem.- 7.6 Projecting the Yield Impact to Products.- 7.7 Projecting the Reliability Impact to Products.- 7.8 Ultra-thin Gate-oxide Issues.- 7.9 The Damage Measurement Problem for Ultra-thin Gate-oxide.- References.