Description
I. Substrate and Material Inspection
For basic raw materials such as silicon wafers, silicon carbide, gallium nitride, photoresist, high-purity reagents, and metal materials
1. Morphology & Dimensional Inspection
o Wafer thickness, warpage, flatness, edge contour, grain size
o Surface defects: scratches, stains, pits, microcrystals, foreign matter
2. Electrical Parameter Inspection
o Resistivity, sheet resistance, carrier concentration, mobility, minority carrier lifetime
3. Composition & Impurity Analysis
o Metallic impurities, ion contamination, organic residues, gaseous impurities, elemental distribution
4. Crystal Quality Analysis
o Lattice defects, dislocations, stacking faults, stress, crystal orientation, epitaxial layer thickness/uniformity
II. Wafer Manufacturing (Photolithography, Etching, Thin Film, Ion Implantation, etc.)
Metrology + Process Analysis
1. Macroscopic Appearance & Defect Inspection
Optical Appearance Inspection: Bright Field / Dark-field optical microscopy: Inspecting pattern misalignment, broken lines, short circuits, pinholes, and residues.
Wafer defect scanning: In-line particle inspection and optical defect inspection (AOI) machines capture minute pattern defects and foreign objects.
Overlay accuracy inspection: Measuring the alignment deviation of multilayer lithography patterns to control the lithography process.
2. Pattern & Dimension Measurement (CD Measurement)
Critical dimension measurement: Etching/lithography linewidth, line spacing, via diameter, trench depth
Main equipment: Scanning electron microscope (SEM) (CD-SEM), optical profilometer
3. Thin Film Process Inspection (Oxidation, Deposition, Metal Layers)
Thin film thickness, refractive index, uniformity, stress, film density
Sheet resistance, sheet resistance uniformity
Multilayer film interface, delamination, and peeling defects
4. Ion Implantation & Doping Analysis
Doping concentration, junction depth, implantation uniformity, and impurity distribution
Post-annealing activation rate and lattice damage
III. Chip Functional Testing (Intermediate Testing/Intermediate Testing) Final Testing (FT/CP) Yield sorting, functional verification, parameter screening – core steps in mass production
1. Wafer Probe Testing (CP/Intermediate Testing) Before wafer dicing, probes contact the pads, testing each chip individually:
o Logic function, memory read/write, analog circuit parameters
o Static current, dynamic power consumption, timing, voltage margin
o Defective chips are marked for subsequent rejection
2. Finished Product Testing (FT/Final Testing, after packaging) After packaging, all chip parameters are tested, categorized, sorted, and marked:
o DC parameters: Voltage, current, impedance, leakage current, withstand voltage
o AC parameters: Transmission delay, frequency, timing, jitter, bandwidth
o Functional testing: Logic operations, instructions, read/write, protocol matching
o Power consumption testing: Static power consumption, dynamic power consumption, standby power consumption
o Sorting by grade: Based on speed, power consumption, and accuracy
3. RF/Analog/ Power Chip Specific Testing
o RF Chips: VSWR, gain, noise figure, phase, spectrum
o Power Devices: Breakdown voltage, on-resistance, threshold voltage, avalanche characteristics, thermal resistance
o Sensors: Sensitivity, linearity, temperature drift, response time
IV. Packaging Process Inspection (Dieting, Bonding, Molding, Surface Mount)
Targeting wafer dicing, wire bonding, flip-chip, molding, ball mounting, and other packaging processes
1. Visual Inspection (Mainly AOI)
o Wafer Dicing: Chipping, cracking, dicing marks, debris
o Bonding: Wire misalignment, broken wires, cold solder joints, poor gold/copper ball morphology
o Molding: Bubbles, cracks, delamination, overflow, marking errors
o BGA/CSP: Missing solder balls, misalignment, bridging, uneven ball diameter
2. Internal Non-Destructive Testing
o X-Ray Inspection: Internal leads, solder balls, vias, voids, delamination, bonding abnormalities (non-destructive testing)
o Ultrasonic scanning (C-Scan): Molding layer, interface delamination, internal voids, cracks (most commonly used for delamination detection)
3. Mechanical & Reliability Preliminary Inspection
o Solder ball push force, lead pull force, shear strength
o Package size, pin coplanarity, appearance dimensional deviation
V. Failure Analysis (FA) (Fault location, root cause analysis, R&D/customer complaints/yield analysis)
After chip/device failure, locating the failure point and analyzing the failure mechanism is the most technically demanding process, divided into non-destructive → semi-destructive → fully destructive processes
1. Non-destructive Disassembly (Non-destructive Analysis)
Visual inspection / optical microscope: burn marks, cracks, corrosion, foreign matter
X-ray: internal broken wires, voids, bond detachment, packaging defects
Ultrasonic SAT: delamination, internal voids, hidden cracks
Infrared thermal imaging IR: locating heat points, leakage points, localized overheating
2. Electrical Failure Location
Curve Tracing IV Test: Identifies short circuits, open circuits, leakage current, and device damage
Optical Emission Microscopy (EMMI): Locates leakage current, PN junction luminescence, and latent failure points
Laser Hotspot Location (LVI/OBIRCH): Locates high resistance, open circuits, and micro-area leakage current
3. Unpacking & Profile Analysis (Semi-destructive/Complete Destructive)
Chemical Unpacking/Mechanical Unpacking: Removes plastic sealant to expose the bare die
Grinding Profile: Observes delamination, voids, solder ball interfaces, and metal layer profiles
Dyeing Test: Detects encapsulation delamination and moisture intrusion paths
4. Microstructure & Composition Analysis (Advanced Characterization)
Scanning Electron Microscopy (SEM): Microstructure, fracture surfaces, defects, and foreign matter morphology
Energy Dispersive X-ray Spectroscopy (EDS/Auger AES): Elemental analysis of foreign matter, contaminants, and corrosion products
Transmission Electron Microscopy (TEM): Lattice, thin film interfaces, nanoscale defects, and dislocations
Atomic Force Microscopy (AFM): Surface roughness, microscopic protrusions/ Indentation
• Secondary ion mass spectrometry (SIMS): In-depth elemental analysis, trace impurity distribution
