Generation of superconductivity by using FET with extremely thin dielectric SrTiO_3

场效应晶体管(FET)因其在有机分子和过渡金属氧化物等绝缘材料中的注入能力而引起人们的极大兴趣。本研究的目的是创造一种新的由氧化物衬底组成的具有高介电常数的FET结构，并测试其电场诱导输运和磁性能。在场效应管中，为了在沟道层中产生大量载流子，必须增大介质层的电容。钛酸锶(STO)是一种著名的介电材料，具有很大的介电常数(10^2-10^4)。为了实现大容量，我们研制了厚度约为几十μm的超薄STO衬底，测试了C_&lt；60&gt；(n型)、并五苯和La_2CuO_4(p型)的FET特性。观察到典型的源漏I-V特性与栅极电压的关系，然而，没有超导的迹象，这表明掺杂的载流子不足以在沟道层中产生超导。必须将载流子密度增加一个数量级，以引起沟道层的电阻率的可检测变化。利用离子交换膜将位于源漏电极下方的STO减薄到几μm是有效的。

Field-effect transistor (FET) has attracted much interest for its ability of career injection into insulating materials such as organic molecules and transition-metal oxides. The purpose of this research is to create a new FET structure consisting of oxides substrates as dielectric layer with high dielectric constants and examine the electric field induced transport and magnetic properties. It is necessary to increase the electric capacitance of a dielectric layer to generate a lot of carrier in the channel layer in FET. SrTiO3 (STO) is a well known dielectric material with a large dielectric constant (10^2-10^4). We have developed extremely thin STO substrate about tens of μm to achieve a large capacitance.FET characteristics were examined for C_<60>(n-type), pentacene and La_2CuO_4(p-type). Typical gate voltage dependence of source-drain I-V characteristics were observed, however, there was no sign of the superconductivity, indicating that the doped carrier is not sufficient to produce superconductivity in the channel layers. It is necessary to increase the carrier density by one order of magnitude to give rise to a detectable change in the resistivity of the channel layers. Thinning of the STO located under the source-drain electrode to a few μm by using the FIB would be effective.