Chip lifecycle / MEMS and sensors lifecycle

MEMS and sensors lifecycle

A MEMS sensor product, such as a motion sensor, pressure sensor, microphone or environmental sensor, and image sensors where the same discipline applies, from application and sensing requirements through transducer and process co-design with multiphysics modelling, MEMS process development, interface ASIC co-design, prototypes and model correlation, packaging that lets the environment reach the sensor, calibration and trim, test and characterisation, and reliability and qualification to production ramp, sustaining and end of life. The output is a calibrated, qualified sensor that performs to its datasheet in the customer's system.

The MEMS and sensors lifecycle journey

12 stages, 12 gates of its own and 9 hand-offs to the Product lifecycle, 3 of the gates technical readiness reviews (TR). Each stop opens its stage; each sign opens its gate. Point at a stop or tab to it to read what the stage is for. What the codes mean

In collaboration with The Digital Electronics Blog (opens in a new tab)

A dashed sign with a TR tag is a technical readiness review gate.

An outlined sign with an arrow is a hand-off: the gate is owned by the Product lifecycle, where this lifecycle hands its work on.

In collaboration with The Digital Electronics Blog (opens in a new tab)

Application & Sensing Requirements
Turning the target applications into a sensing specification: what is measured, over which range, with what noise, bandwidth, accuracy and stability, in which environment, through which interface, at what size, power and cost, and with the mission profile the sensor must survive.
Sensor concept approval gate, owned by the Product lifecycle (Concept approval)Sensing requirements baselined gate
Transducer & Process Co-design
Choosing the transduction principle and the mechanical structure together with the process that can build it, using coupled mechanical, electrostatic, piezoelectric, thermal, fluidic and acoustic models to predict sensitivity, noise, linearity and stress effects before any wafer is run.
Transducer concept selected gateTR1, technical readiness review Sensor development commit gate, owned by the Product lifecycle (Plan approval and development commit)
MEMS Process Development
Developing and freezing the MEMS process flow: structural and sacrificial films with controlled stress, deep etching, release, anti-stiction treatment, wafer bonding and cavity sealing at the required pressure, with the design rules and test structures that let the transducer be laid out and released for prototype wafers.
MEMS process baseline freeze gateTR2, technical readiness review Transducer design release gate
Interface ASIC Co-design
Designing the interface ASIC that reads, drives and conditions the transducer: low-noise front end, conversion, drive and sense loops for resonant sensors, references and bias, digital filtering, trim storage and the sensor interface, verified by co-simulation with a behavioural model of the transducer.
Interface ASIC tape-out gate
Prototype Build & Model Correlation
Building the first MEMS and ASIC wafers into prototype assemblies, measuring them on the bench and with physical stimulus, correlating the measurements with the multiphysics and system models, and shipping engineering samples to lead customers with their limits stated.
First MEMS and ASIC wafers gate Models correlated to prototypes gate Engineering samples gate, owned by the Product lifecycle (Engineering samples)
Packaging That Admits the Environment
Designing a package that protects the MEMS and ASIC while letting the quantity being sensed reach the transducer: acoustic or pressure ports, protective membranes and gels, optical windows for image and light sensors, open cavities for gas and humidity, sealed cavities for inertial sensors, and stress isolation so the package does not become the signal.
Package design freeze gate
Calibration & Trim
Defining how each unit is calibrated and trimmed: which parameters are measured, such as offset, sensitivity, cross-axis response and their temperature behaviour, which physical stimulus and equipment apply them, how coefficients are computed and stored in on-chip memory, and how the compensation in the ASIC and firmware uses them.
Calibration method approved gate
Test & Characterisation
Characterising the sensor across temperature, supply, stimulus and time against its specification, and building the production test and calibration program, from wafer probe of the MEMS and the ASIC to final test with physical stimulus, with limits set from the characterisation data.
Production test and calibration release gate
Reliability & Qualification
Proving the sensor survives its mission profile: mechanical shock, drop and vibration, temperature cycling, humidity and bias, high temperature operating life, stiction and fatigue, hermeticity and outgassing, media exposure for open-port sensors, and parametric drift after stress, to published methods such as JEDEC and, for vehicles, AEC-Q100 and AEC-Q103.
Qualification start gate Qualification passed gateTR3, technical readiness review Production release gate, owned by the Product lifecycle (Production release)
Production Ramp
Scaling MEMS wafer, ASIC wafer, assembly, calibration and test capacity to demand, with calibration throughput and stimulus equipment capacity often setting the pace, while yield, parametric spread and calibration residuals are monitored and driven to their targets.
Volume ramp gate, owned by the Product lifecycle (Volume ramp)Ramp complete gate, owned by the Product lifecycle (Ramp complete)
Volume Production & Sustaining
Running the sensor in volume: watching parametric drift, calibration residuals and field returns, answering customer quality issues, qualifying and notifying process, material and supplier changes, releasing firmware and driver updates, and deciding on derivatives and cost reductions.
Lifecycle review gate, owned by the Product lifecycle (Lifecycle review)
End of Life
Withdrawing the sensor in an orderly way: notifying customers, taking last-time orders, planning the final MEMS and ASIC wafer starts, keeping assembly, calibration equipment and test capacity to the last shipment, and archiving the design, process, calibration and test records.
Discontinuance notice gate, owned by the Product lifecycle (Discontinuance notice)Last-time ship gate, owned by the Product lifecycle (Last-time ship)

An outlined sign with an arrow is a hand-off: the gate is owned by the Product lifecycle, where this lifecycle hands its work on.

Show the journey as a list

Application & Sensing Requirements: Turning the target applications into a sensing specification: what is measured, over which range, with what noise, bandwidth, accuracy and stability, in which environment, through which interface, at what size, power and cost, and with the mission profile the sensor must survive. Gates: Sensor concept approval (at the start, owned by the Product lifecycle: Concept approval), Sensing requirements baselined (at the end).
Transducer & Process Co-design: Choosing the transduction principle and the mechanical structure together with the process that can build it, using coupled mechanical, electrostatic, piezoelectric, thermal, fluidic and acoustic models to predict sensitivity, noise, linearity and stress effects before any wafer is run. Gates: Transducer concept selected (at the end, technical readiness review TR1), Sensor development commit (at the end, owned by the Product lifecycle: Plan approval and development commit).
MEMS Process Development: Developing and freezing the MEMS process flow: structural and sacrificial films with controlled stress, deep etching, release, anti-stiction treatment, wafer bonding and cavity sealing at the required pressure, with the design rules and test structures that let the transducer be laid out and released for prototype wafers. Gates: MEMS process baseline freeze (at the end, technical readiness review TR2), Transducer design release (at the end).
Interface ASIC Co-design: Designing the interface ASIC that reads, drives and conditions the transducer: low-noise front end, conversion, drive and sense loops for resonant sensors, references and bias, digital filtering, trim storage and the sensor interface, verified by co-simulation with a behavioural model of the transducer. Gates: Interface ASIC tape-out (at the end).
Prototype Build & Model Correlation: Building the first MEMS and ASIC wafers into prototype assemblies, measuring them on the bench and with physical stimulus, correlating the measurements with the multiphysics and system models, and shipping engineering samples to lead customers with their limits stated. Gates: First MEMS and ASIC wafers (at the start), Models correlated to prototypes (at the end), Engineering samples (at the end, owned by the Product lifecycle: Engineering samples).
Packaging That Admits the Environment: Designing a package that protects the MEMS and ASIC while letting the quantity being sensed reach the transducer: acoustic or pressure ports, protective membranes and gels, optical windows for image and light sensors, open cavities for gas and humidity, sealed cavities for inertial sensors, and stress isolation so the package does not become the signal. Gates: Package design freeze (at the end).
Calibration & Trim: Defining how each unit is calibrated and trimmed: which parameters are measured, such as offset, sensitivity, cross-axis response and their temperature behaviour, which physical stimulus and equipment apply them, how coefficients are computed and stored in on-chip memory, and how the compensation in the ASIC and firmware uses them. Gates: Calibration method approved (at the end).
Test & Characterisation: Characterising the sensor across temperature, supply, stimulus and time against its specification, and building the production test and calibration program, from wafer probe of the MEMS and the ASIC to final test with physical stimulus, with limits set from the characterisation data. Gates: Production test and calibration release (at the end).
Reliability & Qualification: Proving the sensor survives its mission profile: mechanical shock, drop and vibration, temperature cycling, humidity and bias, high temperature operating life, stiction and fatigue, hermeticity and outgassing, media exposure for open-port sensors, and parametric drift after stress, to published methods such as JEDEC and, for vehicles, AEC-Q100 and AEC-Q103. Gates: Qualification start (at the start), Qualification passed (at the end, technical readiness review TR3), Production release (at the end, owned by the Product lifecycle: Production release).
Production Ramp: Scaling MEMS wafer, ASIC wafer, assembly, calibration and test capacity to demand, with calibration throughput and stimulus equipment capacity often setting the pace, while yield, parametric spread and calibration residuals are monitored and driven to their targets. Gates: Volume ramp (at the start, owned by the Product lifecycle: Volume ramp), Ramp complete (at the end, owned by the Product lifecycle: Ramp complete).
Volume Production & Sustaining: Running the sensor in volume: watching parametric drift, calibration residuals and field returns, answering customer quality issues, qualifying and notifying process, material and supplier changes, releasing firmware and driver updates, and deciding on derivatives and cost reductions. Gates: Lifecycle review (at the end, owned by the Product lifecycle: Lifecycle review).
End of Life: Withdrawing the sensor in an orderly way: notifying customers, taking last-time orders, planning the final MEMS and ASIC wafer starts, keeping assembly, calibration equipment and test capacity to the last shipment, and archiving the design, process, calibration and test records. Gates: Discontinuance notice (at the start, owned by the Product lifecycle: Discontinuance notice), Last-time ship (at the end, owned by the Product lifecycle: Last-time ship).

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