{"id":{"repo_id":"lsu-thes","oai_identifier":"oai:repository.lsu.edu:gradschool_dissertations-1701"},"canonical_url":"https://search.dev.ndltd.org/etd/lsu-thes/oai:repository.lsu.edu:gradschool_dissertations-1701","repository":{"repo_id":"lsu-thes","name":"Lousiana State University","base_url":"https://repository.lsu.edu/do/oai/"},"display":{"title":"Laterally Movable Gate Field Effect Transistor (LMGFET) for microsensor and microactuator applications","abstract":"Laterally Movable Gate Field Effect Transistor (LMGFET) invented at LSU as a microactuator is the subject of study in this research. The gate moving in lateral direction in a LMGFET changes channel width but keeps the channel length and the gap between the metal gate and the gate oxide constant. LMGFET offers linear change in drain current with gate motion and a large displacement range. This research is the first demonstration of LMGFET. In this dissertation, a post-IC LIGA-like process for LMGFET microstructure fabrication has been developed that is compatible with monolithic integration with CMOS circuitry. A two-mask post-IC process has been developed in this research for LMGFET fabrication. This novel process utilizes S1813 photoresist as a sacrificial layer in conjunction with a thicker resist like AZ P4620 or SU-8 as an electroplating mold. New curing temperatures for the sacrificial layer photoresist have been determined for this purpose. LMGFET microstructures have been successfully integrated with CMOS circuitry on the same chip to form integrated microsystem. LMGFET microstructure driven by a comb-drive with serpentine retaining spring shows sensitivities Sel of 2 and 1.43 nA/V respectively at 5 and 25 Hz. These numbers reflect that LMGFET is capable of measuring nm range displacement. Electrical characteristics of a depletion type LMGFET structure are measured and show an average sensitivity Sl of - 4 µA/µm at drain to source voltage VDS of 10 V with the gate shorted to source. Several applications of microsystems utilizing LMGFET microstructures as a position sensor or an accelerometer, a spectrum analyzer or an electro-mechanical filter and a mechanical/optical switch are described.","abstract_html":"Laterally Movable Gate Field Effect Transistor (LMGFET) invented at LSU as a microactuator is the subject of study in this research. The gate moving in lateral direction in a LMGFET changes channel width but keeps the channel length and the gap between the metal gate and the gate oxide constant. LMGFET offers linear change in drain current with gate motion and a large displacement range. This research is the first demonstration of LMGFET. In this dissertation, a post-IC LIGA-like process for LMGFET microstructure fabrication has been developed that is compatible with monolithic integration with CMOS circuitry. A two-mask post-IC process has been developed in this research for LMGFET fabrication. This novel process utilizes S1813 photoresist as a sacrificial layer in conjunction with a thicker resist like AZ P4620 or SU-8 as an electroplating mold. New curing temperatures for the sacrificial layer photoresist have been determined for this purpose. LMGFET microstructures have been successfully integrated with CMOS circuitry on the same chip to form integrated microsystem. LMGFET microstructure driven by a comb-drive with serpentine retaining spring shows sensitivities Sel of 2 and 1.43 nA/V respectively at 5 and 25 Hz. These numbers reflect that LMGFET is capable of measuring nm range displacement. Electrical characteristics of a depletion type LMGFET structure are measured and show an average sensitivity Sl of - 4 µA/µm at drain to source voltage VDS of 10 V with the gate shorted to source. Several applications of microsystems utilizing LMGFET microstructures as a position sensor or an accelerometer, a spectrum analyzer or an electro-mechanical filter and a mechanical/optical switch are described.","abstract_has_math":false,"creators":["Song, In-Hyouk"],"institution":"Electrical and Computer Engineering","degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation","degree_discipline":"Electrical and Computer Engineering","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2005,"date_issued":"2005-01-01T08:00:00Z","date_published":"2005-01-01T08:00:00Z","updated_at":"2026-07-24T02:57:56Z","subjects":["monolithic integration","MEMS","LMGFET","laterally movable gate FET","post-IC fabrication","LIGA-like","microsensor","microactuator"],"languages":[],"rights":["unrestricted","Release the entire work immediately for access worldwide."],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["etd-04152005-002604","https://repository.lsu.edu/gradschool_dissertations/702"],"render_values":[{"text":"etd-04152005-002604","href":null,"code":true},{"text":"https://repository.lsu.edu/gradschool_dissertations/702","href":"https://repository.lsu.edu/gradschool_dissertations/702","code":true}]}]},"links":{"outbound_url":"https://doi.org/10.31390/gradschool_dissertations.702","outbound_label":"DOI","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Song, In-Hyouk"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2005-03-31"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2022-05-12T23:09:42Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical and Computer Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy (PhD)"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Electrical and Computer Engineering"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["monolithic integration","MEMS","LMGFET","laterally movable gate FET","post-IC fabrication","LIGA-like","microsensor","microactuator"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["unrestricted","Release the entire work immediately for access worldwide."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["etd-04152005-002604","10.31390/gradschool_dissertations.702","https://repository.lsu.edu/gradschool_dissertations/702"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Laterally Movable Gate Field Effect Transistor (LMGFET) invented at LSU as a microactuator is the subject of study in this research. The gate moving in lateral direction in a LMGFET changes channel width but keeps the channel length and the gap between the metal gate and the gate oxide constant. LMGFET offers linear change in drain current with gate motion and a large displacement range. This research is the first demonstration of LMGFET. In this dissertation, a post-IC LIGA-like process for LMGFET microstructure fabrication has been developed that is compatible with monolithic integration with CMOS circuitry. A two-mask post-IC process has been developed in this research for LMGFET fabrication. This novel process utilizes S1813 photoresist as a sacrificial layer in conjunction with a thicker resist like AZ P4620 or SU-8 as an electroplating mold. New curing temperatures for the sacrificial layer photoresist have been determined for this purpose. LMGFET microstructures have been successfully integrated with CMOS circuitry on the same chip to form integrated microsystem. LMGFET microstructure driven by a comb-drive with serpentine retaining spring shows sensitivities Sel of 2 and 1.43 nA/V respectively at 5 and 25 Hz. These numbers reflect that LMGFET is capable of measuring nm range displacement. Electrical characteristics of a depletion type LMGFET structure are measured and show an average sensitivity Sl of - 4 µA/µm at drain to source voltage VDS of 10 V with the gate shorted to source. Several applications of microsystems utilizing LMGFET microstructures as a position sensor or an accelerometer, a spectrum analyzer or an electro-mechanical filter and a mechanical/optical switch are described."]},{"key":"dc:title","label":"Title","values":["Laterally Movable Gate Field Effect Transistor (LMGFET) for microsensor and microactuator applications"]}]}],"canonical_facts":{"dc:creator":["Song, In-Hyouk"],"dc:date":["2005-03-31"],"dc:date.available":["2022-05-12T23:09:42Z"],"dc:description.abstract":["Laterally Movable Gate Field Effect Transistor (LMGFET) invented at LSU as a microactuator is the subject of study in this research. The gate moving in lateral direction in a LMGFET changes channel width but keeps the channel length and the gap between the metal gate and the gate oxide constant. LMGFET offers linear change in drain current with gate motion and a large displacement range. This research is the first demonstration of LMGFET. In this dissertation, a post-IC LIGA-like process for LMGFET microstructure fabrication has been developed that is compatible with monolithic integration with CMOS circuitry. A two-mask post-IC process has been developed in this research for LMGFET fabrication. This novel process utilizes S1813 photoresist as a sacrificial layer in conjunction with a thicker resist like AZ P4620 or SU-8 as an electroplating mold. New curing temperatures for the sacrificial layer photoresist have been determined for this purpose. LMGFET microstructures have been successfully integrated with CMOS circuitry on the same chip to form integrated microsystem. LMGFET microstructure driven by a comb-drive with serpentine retaining spring shows sensitivities Sel of 2 and 1.43 nA/V respectively at 5 and 25 Hz. These numbers reflect that LMGFET is capable of measuring nm range displacement. Electrical characteristics of a depletion type LMGFET structure are measured and show an average sensitivity Sl of - 4 µA/µm at drain to source voltage VDS of 10 V with the gate shorted to source. Several applications of microsystems utilizing LMGFET microstructures as a position sensor or an accelerometer, a spectrum analyzer or an electro-mechanical filter and a mechanical/optical switch are described."],"dc:identifier":["etd-04152005-002604","10.31390/gradschool_dissertations.702","https://repository.lsu.edu/gradschool_dissertations/702"],"dc:rights":["unrestricted","Release the entire work immediately for access worldwide."],"dc:subject":["monolithic integration","MEMS","LMGFET","laterally movable gate FET","post-IC fabrication","LIGA-like","microsensor","microactuator"],"dc:title":["Laterally Movable Gate Field Effect Transistor (LMGFET) for microsensor and microactuator applications"],"thesis:degree_discipline":["Electrical and Computer Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy (PhD)"],"thesis:institution_name":["Electrical and Computer Engineering"]},"updated_at":"2026-07-24T02:57:56Z"}