Project description

In the Large-Area Thin-film Transistor Electronics (LATTE) group of imec, we design the next generation of circuits using thin-film transistors (TFT) [1, 2]. The underlying transistor technologies for these devices can be low temperature polycrystalline Silicon (LTPS) or Indium-Gallium-Zinc Oxide (IGZO), both deposited on flexible substrates, and enable us to realize flexible circuits. Recently, we have already developed various state-of-the-art analog/mixed-signal circuit blocks, including OpAmps and comparators [2, 3]. Further accurate characterization of the existing blocks (OpAmps, comparators [3]) is required to firstly enhance the process design kits (PDKs) and device models, and subsequently to optimize the designs.

Project objectives

In this internship you will characterize various iterations of comparators and OpAmps, analyse their performance and propose improvements to these building blocks leading to next-generation comparator and OpAmp design with improved performance and stability enabling various large area applications [4,5,6]. You will evaluate the following performance metrics of these cells, including speed, gain, offset, noise, power dissipation, ... Depending on the internship duration, you will as a next step focus to design the next generation test circuits. Based on the duration and the quality of the results, we also target to share the characterization results in a publication or conference.

Project tasks

As the intern, you will follow these steps:

• Background evaluation of the specifics of IGZO and LTPS technologies for analog/mixed-signal circuit design
• Measure basic circuits with available lab equipment
• Compile python/matlab scripts to efficiently interact with equipment and plot results
• Optional: use the learnings to design the next iteration of the analog/mixed-signal signal blocks.
• Optional: write a research paper on the findings

Requirements

To bring this project to a satisfying conclusion, you will require:

• A background in circuit design
• Preferably enrolled in a circuit design master or related
• Enjoy getting your hands “dirty” in the lab
• Strong communication skills
• Lots of positive energy and initiative
• The desire to be part of an enthusiastic and supportive team

Depending on the time available, this internship can be anywhere from 3 to 9 months.

Further reading

[1] Multi-project wafers for flexible TF electronics by independent foundries, https://doi.org/10.1038/s41586-024-07306-2

[2] Sara Hong, et al, “Characterization of a-IGZO TFT-based Operational Amplifier and Comparator for High-Speed Analog-to-Digital Converter on Flexible Substrate”, IDW 2023, 10.36463/idw.2023.1108

[3] S. Mojtaba Sadati Faramarzi, et al, “High performance 6V and 64.2dB LTPS TFT Operational Amplifier for Integrated Read-out in Large Area Sensing Arrays”, ICECS 2024,

[4] S. Mojtaba Sadati Faramarzi, et al, "Flexible TFT Read-Out Circuit Blocks for Large Area Sensor Array System Integration Measuring Photovoltaic Modules and Batteries," in IEEE Journal on Flexible Electronics, July 2024, doi: 10.1109/JFLEX.2024.3433322.

[5] H. Londoño‐Ramírez et al., “Multiplexed Surface Electrode Arrays Based on Metal Oxide Thin‐Film Electronics for High‐Resolution Cortical Mapping,” Advanced Science, Mar. 2024, doi: 10.1002/advs.202308507.

[6] E. Georgitzikis et al., “78‐2: A flat‐panel‐display compatible ultrasound platform,”Symp Digest of Tech Papers, Jun. 2023, doi: 10.1002/sdtp.16764.