Project Title: Reduction of Breakage Defects for Substrate Yield Improvement on
OSRAM Devices
Project Case: Breakage defects (BST/CBSTC/NED) yield loss was significant on
multiple substrates for OOSD Devices (NLB, NLT). Yield loss on substrates results
in the rejection of affected tiles which impacts the customers due to low product
yield
Aim of the Project: To reduce/eliminate substrate yield loss by reducing in-line
defects
Case Study (BST/CBSTC/NED)
Effects: Up for Rejection
Process Involved: Clean A, Batch Clean, Seed Metal A (Sputtering)
Cause 1: Materials and Method related to failure modes
 Standard Operating Procedure reviews
Cause 2: Measurement (Not Applicable)
Cause 3: Environment
 Orderliness of the workplace (6S)
 Kaizen Elimination of Wastes
Cause 4: Manpower (Human Errors)
 Check if any inexperienced operator or new hires joined the team and were
performing tasks
 Standard Operating Procedure reviews and Work Instruction
Cause 5: Machine
 Check if any changes were made before and after the dates when the defect were first
seen
 Checking if there are misalignments in the machine parts that needs to fix
 Review preventive maintenance.
Measurement Tools to use: Trend Chart for Defects (Regression, Pareto)
Affected Critical to Quality (CTQ): Yield
Project Title: Reduction of Four Wire Errors for Substrate Yield Improvement
Project Case: Yield loss for Four Wire Error is critical on various substrates. Yield
loss on substrates results in the rejection of affected tiles which impacts the
customers due to low product yield
Aim of the Project: To reduce/eliminate substrate yield loss
Case Study (Seed Metal Thickness Out of Specifications)
Potential Effects:
If high thickness, seed metal remain. Reject affected tiles
If low thickness, will fail at O/S Test. Tiles affected of FWE/FWO will be rejected
Process Involved: Seed Metal A (Sputtering)
Cause 1: Materials and Method related to failure modes
 Standard Operating Procedure reviews
Cause 2: Measurement
 SOP reviews for specifications
 Reading confirmations by multiple operators (monitoring logs)
 Bowman/Fischerscope reading and calibration on sputter thickness (Titanium and
Copper)
 Power output emission monitoring during sputtering
Cause 3: Environment (Not Applicable)
Cause 4: Manpower (Human Errors)
 Review preventive maintenance cycle procedures
 Check shift pass-down notes
 Check if any inexperienced operator or new hires joined the team and were
performing tasks
Cause 5: Machine
 Check if any changes were made before and after the dates when the defect were first
seen
 Checking of shields and other parts of the main chamber during sputter target
replacement.
Measurement Tools to use: CpK Trend Chart
Affected Critical to Quality (CTQ): Yield