A PROCESS FOR THE MANUFACTURE OF ION-SENSITIVE FIELD-EFFECT TRANSISTOR (ISFET) WITH A HIGH ASPECT RATIOIN260489A1

摘要

Title; A process for the manufacture of ion-sensitive field-effect transistor (ISFET) with a high aspect ratio and ion-sensitive field-effect transistor (ISFET) made thereby, leading to fabrication of sensors with enhanced performance for chemical and biological applications. The process disclosed enables to overcome the implementational problem of high drain-source leakage current encountered in extremely large aspect ratio ISFETs. It comprises chromium-gold metallization followed by pre-sintering and cleaning in hot HNOb, water rinsing, dip in dilute HF and thorough water rinsing, after which the wafers are sintered in forming gas, with similar cleaning performed again after dicing of the wafers into chips. The significant advantage of the process is that the resulting structure, due to its large intrinsic amplification, has been found to detect several ionic specimens such as hydrogen ions and ions like potassium, sodium, calcium, iron, zinc and cobalt, enabling fabrication of a wide class of sensors for chemical and biological applications, either as such, or by coating with the necessary ion-selective membrane or by immobilization of the required enzyme. The novel process serves to build a versatile platform for fabrication of diverse sensors.