質 ガリウム窒化物のウエファー & サファイアのウエファー メーカー

Comprehensive Overview of Advanced Ceramics Used in Semiconductor Equipment   Precision ceramic components are essential elements in core equipment for key semiconductor manufacturing processes such as photolithography, etching, thin film deposition, ion implantation, and CMP. These parts—including bearings, guide rails, chamber liners, electrostatic chucks, and robotic arms—are especially critical inside process chambers, where they serve functions such as support, protection, and flow control. This article provides a systematic overview of how precision ceramics are applied in major semiconductor fabrication equipment.       Front-End Processes: Precision Ceramics in Wafer Fabrication Equipment 1. Photolithography Equipment   To ensure high process accuracy in advanced photolithography systems, a wide range of ceramic components with excellent multifunctionality, structural stability, thermal resistance, and dimensional precision are used. These include electrostatic chucks, vacuum chucks, blocks, water-cooled magnet bases, reflectors, guide rails, stages, and mask holders.   Key ceramic components: Electrostatic chuck, motion stage   Main materials:Electrostatic chucks: Alumina (Al₂O₃), Silicon Nitride (Si₃N₄), Motion stages: Cordierite ceramics, Silicon Carbide (SiC)   Technical challenges: Complex structure design, raw material control and sintering, temperature management, and ultra-precision machining. The material system of lithography motion stages is crucial for achieving high accuracy and scanning speed. Materials must feature high specific stiffness and low thermal expansion to withstand high-speed movements with minimal distortion—thus improving throughput and maintaining precision.       2. Etching Equipment   Etching is critical for transferring circuit patterns from the mask to the wafer. Key ceramic components used in etching tools include the chamber, viewport window, gas distribution plate, nozzles, insulator rings, cover plates, focus rings, and electrostatic chucks. Key ceramic components: Electrostatic chuck, focus ring, gas distribution plate   Main ceramic materials: Quartz, SiC, AlN, Al₂O₃, Si₃N₄, Y₂O₃     Etching Chamber: With shrinking device geometries, stricter contamination controls are required. Ceramics are preferred over metals to prevent particle and metal ion contamination.     Material requirements: High purity, minimal metal contamination Chemically inert, especially to halogen-based etching gases High density, minimal porosity Fine grain, low grain boundary content Good mechanical machinability Specific electrical or thermal properties if needed   Gas Distribution Plate: Featuring hundreds or thousands of precision-drilled microholes, these plates uniformly distribute process gases, ensuring consistent deposition/etching.   Challenges: Demands on hole diameter uniformity and burr-free inner walls are extremely high. Even slight deviations can cause film thickness variation and yield loss.   Main materials: CVD SiC, Alumina, Silicon Nitride   Focus Ring: Designed to balance plasma uniformity and match the conductivity of the silicon wafer. Compared to traditional conductive silicon (which reacts with fluorine plasma to form volatile SiF₄), SiC offers similar conductivity and superior plasma resistance, enabling longer life.   Material: Silicon Carbide (SiC) ​       3. Thin Film Deposition Equipment (CVD / PVD)     In CVD and PVD systems, key ceramic parts include electrostatic chucks, gas distribution plates, heaters, and chamber liners. Key ceramic components: Electrostatic chuck, ceramic heater   Main materials: Heaters: Aluminum Nitride (AlN), Alumina (Al₂O₃)   Ceramic Heater: A critical component located inside the process chamber, directly in contact with the wafer. It supports the wafer and ensures uniform, stable process temperatures across its surface. ​   Back-End Processes: Precision Ceramics in Packaging & Testing Equipment       1. CMP (Chemical Mechanical Planarization) CMP equipment utilizes ceramic polishing plates, handling arms, alignment platforms, and vacuum chucks for high-precision surface planarization.   2. Wafer Dicing and Packaging Equipment Key ceramic components: Dicing Blades: Diamond-ceramic composites, cutting speed ~300 mm/s, edge chipping

How does stress develop in quartz materials?     1. Thermal Stress During Cooling (Primary Cause) Quartz glass develops internal stress when exposed to non-uniform temperatures. At any given temperature, quartz glass exhibits a specific atomic structure that is most "suitable" or stable under those thermal conditions. The spacing between atoms changes with temperature—this is known as thermal expansion. When quartz glass experiences uneven heating or cooling, differential expansion occurs.   Stress typically arises when hotter regions attempt to expand but are constrained by surrounding cooler areas. This results in compressive stress, which usually does not damage the product. If the temperature is high enough to soften the quartz glass, the stress may be relieved. However, if the cooling process is too rapid, the viscosity of the material increases too quickly, and the atomic structure cannot adjust in time to accommodate the temperature drop. This leads to the formation of tensile stress, which is more likely to cause structural damage.   Stress increases progressively as the temperature drops and can reach high levels after cooling ends. In fact, when the viscosity of quartz glass exceeds 10^4.6 poise, the temperature is referred to as the strain point—at this stage, the viscosity is too high for stress relaxation to occur.     Normal>Deformed>           2. Stress from Phase Transition and Structural Relaxation   Metastable Structural Relaxation: In the molten state, quartz exhibits a highly disordered atomic arrangement. During cooling, atoms attempt to transition toward a more stable configuration. However, due to the high viscosity of the glassy state, atomic movement is limited, leaving the structure in a metastable state. This generates relaxation stress, which may be slowly released over time (as observed in the aging phenomenon in glasses).   Microscopic Crystallization Tendency: If molten quartz is held at specific temperature ranges (e.g., near the devitrification temperature), microscopic crystallization may occur (e.g., precipitation of cristobalite microcrystals). The volume mismatch between crystalline and amorphous phases can induce phase transition stress.       3. External Loads and Mechanical Actions 1) Stress Induced During Machining Mechanical processing such as cutting, grinding, and polishing can introduce surface lattice distortion, resulting in machining stress. For example, cutting with a grinding wheel generates localized heat and mechanical pressure at the edge, leading to stress concentration. Improper techniques during drilling or slotting can create notches that act as crack initiation sites.   2) Load Stress in Service Environments When used as a structural material, fused quartz may bear mechanical loads such as pressure or bending, generating macroscopic stress. For instance, quartz containers holding heavy substances develop bending stress.       4. Thermal Shock and Sudden Temperature Changes 1) Instantaneous Stress from Rapid Heating or Cooling Although fused quartz has an extremely low coefficient of thermal expansion (~0.5×10⁻⁶/°C), rapid temperature changes (e.g., heating from room temperature to high temperatures or immersion in ice water) can result in localized thermal expansion or contraction, causing instantaneous thermal stress. Laboratory glassware made of quartz may fracture under such thermal shocks. 2) Cyclic Temperature Fluctuations Under long-term cyclic thermal environments (e.g., furnace linings or high-temperature optical windows), repeated thermal expansion and contraction can accumulate fatigue stress, accelerating material aging and cracking.           5. Chemical Effects and Stress Coupling 1) Corrosion and Dissolution Stress When fused quartz comes into contact with strong alkaline solutions (e.g., NaOH) or high-temperature acidic gases (e.g., HF), its surface may undergo chemical corrosion or dissolution, disrupting structural uniformity and causing chemical stress. Alkaline attack can cause surface volume changes or form microcracks. 2) CVD-Induced Stress In chemical vapor deposition (CVD) processes, coating quartz with materials like SiC may introduce interfacial stress due to mismatches in thermal expansion coefficients or elastic moduli between the film and the substrate. Upon cooling, such stress may cause film delamination or substrate cracking.     6. Internal Defects and Impurities 1) Bubbles and Embedded Impurities During melting, residual gas bubbles or impurities (e.g., metal ions or unmelted particles) may become trapped in fused quartz. The difference in physical properties (e.g., thermal expansion coefficient or modulus) between these inclusions and the surrounding glass can lead to localized stress concentration, increasing the risk of crack formation around bubbles under load. 2) Microcracks and Structural Defects Impurities in raw materials or melting defects can lead to microcracks in the quartz. When subjected to external loads or temperature fluctuations, stress concentration at crack tips can intensify, accelerating crack propagation and ultimately compromising the material's integrity.  

Comprehensive Analysis of Silicon Wafer Parameters: From Fundamentals to Applications       I. Introduction   Silicon wafers are the cornerstone of the semiconductor industry, widely used in chip manufacturing, photovoltaics, MEMS (Micro-Electro-Mechanical Systems), and more. Their performance directly impacts the yield, stability, and efficiency of end products. Thus, understanding silicon wafer parameters is critical for professionals in related fields. This article provides a detailed overview of silicon wafer characteristics, including crystal structure, geometric dimensions, surface quality, electrical properties, mechanical performance, and practical applications.       Semiconductor Wafer Fabrication       II. Basic Concepts and Classification of Silicon Wafers   1. Definition of Silicon Wafers   Silicon wafers are thin slices of monocrystalline silicon produced through cutting, grinding, and polishing processes. Typically circular, they are used in integrated circuits (ICs), sensors, optoelectronic devices, etc. Based on manufacturing methods and applications, silicon wafers are categorized as:   · CZ (Czochralski) Wafers: High-purity, uniform monocrystalline silicon for precision ICs.   · FZ (Float-Zone) Wafers: Ultra-low dislocation density, ideal for advanced-node chips.   · Multicrystalline Wafers: Cost-effective for mass production (e.g., solar cells).   · Sapphire Substrates: Non-silicon but used in LEDs due to high hardness and thermal stability.       ZMSH's 8inch silicon wafers       III. Key Parameters of Silicon Wafers   1. Geometric Dimensions   · Thickness: Ranges from 200μm to 750μm (±2μm tolerance). Ultra-thin wafers can be