标签: EFM

半导体前端制造wafer fab中必须要做静电防护的一个重要光刻工具-photomask（reticles），否则静电导致的photomask的CD（Critical Dimension，）不良（对65nm制程技术及以下有位敏感）必然会导致半导体器件的光刻良率损失甚至于全部报废。 转载自微信公众号“ESDiS Release”。原文链接： https://mp.weixin.qq.com/s?__biz=MzkzMDU2MDkwNQ==&mid=2247483725&idx=1&sn=b99dfbc91d9e172b1c1125bd80771d63&chksm=c2792fabf50ea6bdea3c11752a06bc292c90345525f381578c6efc6d54d9376a91ff44158905#rd Keywords of Glossary Reticles, also called as photomask, it usually utilize quartz or glass as the substrate and coated with an opaque film (often chrome) of the designed pattern on it which is etched the design of the device being manufactured. SMIF pod, it provides reticles users with a standard mechanical interface (SMIF) to the safe handling, storage and transportations within fabs. EFM, it refers to electric field induced ion migrations (mainy for chrome ions coated on reticles). ESD, Electro-Static Discharge, it refers to the abrupt transfer of static charges under the influences of electric fields. The Electrostatics Susceptibility of Reticles Regarding the features of large amounts of diverse chrome patterns with micro spaces (presently most reticles of IC products fall below 1um range) on the insulating glass or quartz, reticles would exhibit very high susceptibilities to electrostatics, involving EFM and ESD events. Figure 1. the micro level isolated chromes patterns of SEMI reticles Regarding EFM problems of reticles, usually it occurs when reticles approaches higher electrostatic sources or reticles substrate was electrostatically charged up higher during handlings in fabs. EFM would induce reticles inspection failures of CD (critical dimension) variations. EFM impacts of reticles could be accumulated over a long time electrostatics exposures. Figure 2. CD failures of reticles caused by EFM events Regarding ESD problems of reticles, usually it occurs when reticles are exposed to very higher electrostatics than EFM events. ESD events of reticles (within reticles or between reticles and other items involved) often lead to chrome patterns with damages of mice bits or short bridges. Figure 3. reticles with ESD damages of mice bites type Figure 4. reticles with ESD damages of short bridges and / or melting Electrostatics Risks evaluation Method Wafer fabs could obtain the appropriate commercial E-reticles product to evaluate the electrostatics risks under control or out of control. This evaluation data could specifically help fabs to pin out the real electrostatics risks and take effective countermeasures for improvement. Fabs could also design and manufacture the E reticles by themselves. Figure 5. E reticles used to evaluate reticles electrostatics risks The Electrostatics Controls of Reticles in SEMI Wafer Fabs The electrostatics controls of recticles in wafer fabs involves storage, handlings in production automation equipment (mainly for lithography) and transportations. Storage: reticles shall be enclosed in the SMIF pods or boxes which could provide the complete electrostatics protections against EFM and ESD. Handlings within automation equipment: the enclosed electric field shielding approach cannot be feasible within automations, the environment of reticles moving must be controlled at low electrostatics level and AC fields especially near reticles needs also be controlled at low levels. Transportations: Due to many insulating materials used in fabs, reticles transportations shall be put into SMIF pods with fully electrostatics protections prior to transportations.

广义上刷新静电领域的主要专业术语再认知：Electrostatics （静电学）, electrostatic charge （静电）, ESD （静电释放或静电放电）。 同文转自微信公众号“ESDiS Release”。 You may need to renew your industrial understandings about the relations and differences between the technical glossaries of electrostatics, electrostatic charge and ESD. Definitions Review Electrostatics:Electrostatics is the study of electric charges at rest. (referred to IEEE digital library) Electrostatic charge: also called as static electricity. it refers to electric charge at rest. (referred to glossary document of ESD ADV1.0) ESD: Electro-Static Discharge, it refers to the rapid, spontaneous transfer of electrostatic charge induced by a high electrostatic field. (Note: Usually, the charge flows through a spark between two bodies at different electrostatic potentials as they approach one another). (referred to glossary document of ESD ADV1.0) Relations and Differences Based on the above definitions, electrostatics is the broadest term to cover all aspects related with electric charges.And the plasma processes in microelectronics manufacturing industries could be also included. The industrial problems induced by electrostatics usually are caused by the movements of electric charges by the influence of the high electric fields. Regarding the term of ESD, it is just one branch in electrostatics which is one kind of particular case of rapid transfers of electric charges by high electric fields. The Broad sense of the industrial Problems of electrostatics in microelectronics manufacturing industries To the broad sense to look into nowadays microelectronics manufacturing industries, the industrial problems caused by electrostatics could involve ESA, ESD, EFM and PID. The problem of ESA (Electro-Static Attraction) group usually includes particle contaminations, process deviations by the effects of ESA. The problem of ESD (Electro-Static Discharge) group usually refers to the microelectronic device failure caused by ESD events. The problem of EFM (Electric Field induced ions migration) group usually occur in the field sensitive microelectronics devices while the ions migrate within devices under the influence of the high electric fields. EFM usually induce problems of CD (Critical Dimensions) failures or electrical leakage of microelectronics. The problem of PID (Plasma process Induced Damage) group usually refers to the insulating dielectrics (such as gate oxide layer, interlayer) failures caused by plasma effects.