Dielectric layers containing a chemical vapor deposited hafnium oxide and an electron beam evaporated lanthanide oxide and a method of fabricating such a dielectric layer produce a reliable dielectric layer having an equivalent oxide thickness thinner than attainable using SiO.sub.2. Forming a layer of hafnium oxide by chemical vapor deposition and forming a layer of a lanthanide oxide by electron beam evaporation, where the layer of hafnium oxide is adjacent and in contact with the layer of lanthanide, provides a dielectric layer with a relatively high dielectric constant as compared with silicon dioxide. Forming the layer of hafnium oxide by chemical vapor deposition using precursors that do not contain carbon permits the formation of the dielectric layer without carbon contamination. The dielectric can be formed as a nanolaminate of hafnium oxide and a lanthanide oxide.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is related to the co-filed and commonly assigned U.S. patent application, Ser. No. 10/602,323, entitled "Lanthanide Oxide/Hafnium Oxide Dielectric Layers," which is hereby incorporated by reference in its entirety.
Disclosed is a capacitor with a dielectric layer having a low equivalent oxide thickness compared to a HfO.sub.2 layer and capable of decreasing a level of a leakage current incidence and a method for fabricating the same. Particularly, the capacitor includes: a bottom electrode; a Hf.sub.1-xLa.sub.xO layer on the bottom electrode; and a top electrode on the Hf.sub.1-xLa.sub.xO layer, wherein x is an integer. The method includes the steps of: forming at least one bottom electrode being made of polysilicon doped with impurities; nitriding a surface of the bottom electrode; depositing the amorphous Hf.sub.1-xLa.sub.xO layer on the nitrided surface of the bottom electrode; performing a thermal process for crystallizing the amorphous Hf.sub.1-xLa.sub.xO layer and removing impurities existed within the Hf.sub.1-xLa.sub.xO layer; nitriding a surface of the crystallized Hf.sub.1-xLa.sub.xO layer; and forming the top electrode being made of polysilicon doped with impurities on the nitrided surface of the crystallized Hf.sub.1-xLa.sub.xO layer.
Embodiments in accordance with the present invention provide alternative materials, and methods of forming such materials, that are effective as dielectric layers. Such embodiments include forming metal-containing dielectric layers over a silicon-containing substrate where a metal-containing layer is first formed and that treated to form a dielectric layer. Dielectric layers formed by methods of the present invention have a dielectric constant greater than that of silicon dioxide, and can have an equivalent oxide thickness of less than 2 nanometers. Such dielectric layers are useful in the forming of a variety of semiconductor devices such as transistors, capacitors and the like where such devices and integrated circuits formed from such devices are encompassed by embodiments in accordance with the present invention.
Embodiments in accordance with the present invention provide alternative materials, and methods of forming such materials, that are effective as dielectric layers. Such embodiments include forming metal-containing dielectric layers over a silicon-containing substrate where a metal-containing layer is first formed and that treated to form a dielectric layer. Dielectric layers formed by methods of the present invention have a dielectric constant greater than that of silicon dioxide, and can have an equivalent oxide thickness of less than 2 nanometers. Such dielectric layers are useful in the forming of a variety of semiconductor devices such as transistors, capacitors and the like where such devices and integrated circuits formed from such devices are encompassed by embodiments in accordance with the present invention.
Embodiments in accordance with the present invention provide alternative materials, and methods of forming such materials, that are effective as dielectric layers. Such embodiments include forming metal-containing dielectric layers over a silicon-containing substrate where a metal-containing layer is first formed and that treated to form a dielectric layer. Dielectric layers formed by methods of the present invention have a dielectric constant greater than that of silicon dioxide, and can have an equivalent oxide thickness of less than 2 nanometers. Such dielectric layers are useful in the forming of a variety of semiconductor devices such as transistors, capacitors and the like where such devices and integrated circuits formed from such devices are encompassed by embodiments in accordance with the present invention.
The use of atomic layer deposition (ALD) to form an amorphous dielectric layer of titanium oxide (TiO.sub.x) doped with lanthanide elements, such as samarium, europium, gadolinium, holmium, erbium and thulium, produces a reliable structure for use in a variety of electronic devices. The dielectric structure is formed by depositing titanium oxide by atomic layer deposition onto a substrate surface using precursor chemicals, followed by depositing a layer of a lanthanide dopant, and repeating to form a sequentially deposited interleaved structure. Such a dielectric layer may be used as the gate insulator of a MOSFET, as a capacitor dielectric, or as a tunnel gate insulator in flash memories, because the high dielectric constant (high-k) of the film provides the functionality of a thinner silicon dioxide film, and because the reduced leakage current of the dielectric layer when the percentage of the lanthanide element doping is optimized.
