Abstract:
A first electrode layer for a Metal-Insulator-Metal (MIM) DRAM capacitor is formed wherein the first electrode layer contains a conductive metal oxide formed using a high temperature, low pressure ALD process. The high temperature ALD process results in a layer with enhanced crystallinity, higher density, reduced shrinkage, and lower carbon contamination. The high temperature ALD process can be used for either or both the bottom electrode and the top electrode layers.
Abstract:
A metal oxide first electrode material for a MIM DRAM capacitor is formed wherein the first and/or second electrode materials or structures contain layers having one or more dopants up to a total doping concentration that will not prevent the electrode materials from crystallizing during a subsequent anneal step. Advantageously, the electrode doped with one or more of the dopants has a work function greater than about 5.0 eV. Advantageously, the electrode doped with one or more of the dopants has a resistivity less than about 1000 μΩcm. Advantageously, the electrode materials are conductive molybdenum oxide.
Abstract:
A method for fabricating a DRAM capacitor stack is described wherein the dielectric material is a multi-layer stack formed from a highly-doped material combined with a lightly or non-doped material. The highly-doped material remains amorphous with a crystalline content of less than 30% after an annealing step. The lightly or non-doped material becomes crystalline with a crystalline content of equal to or greater than 30% after an annealing step. The dielectric multi-layer stack maintains a high k-value while minimizing the leakage current and the EOT value.
Abstract:
A method for fabricating a dynamic random access memory (DRAM) capacitor stack is disclosed wherein the stack includes a first electrode, a dielectric layer, and a second electrode. The first electrode is formed from a conductive binary metal compound and the conductive binary metal compound is annealed in a reducing atmosphere to promote the formation of a desired crystal structure. The binary metal compound may be a metal oxide. Annealing the metal oxide (i.e. molybdenum oxide) in a reducing atmosphere may result in the formation of a first electrode material (i.e. MoO2) with a rutile-phase crystal structure. This facilitates the formation of the rutile-phase crystal structure when TiO2 is used as the dielectric layer. The rutile-phase of TiO2 has a higher k value than the other possible crystal structures of TiO2 resulting in improved performance of the DRAM capacitor.
Abstract:
A method for fabricating a dynamic random access memory (DRAM) capacitor includes forming a first electrode layer, forming a catalytic layer on the first electrode layer, optionally annealing the catalytic layer, forming a dielectric layer on the catalytic layer, optionally annealing the dielectric layer, forming a second electrode layer on the dielectric layer, and optionally annealing the capacitor stack. Advantageously, the electrode layers are TiN, the catalytic layer is MoO2−x where x is between 0 and 2, and the physical thickness of the catalytic layer is between about 0.5 nm and about 10 nm, and the dielectric layer is ZrO2.
Abstract:
A method for forming a DRAM MIM capacitor stack having low leakage current and low EOT involves the use of an compound high k dielectric material. The dielectric material further comprises a dopant. One component of the compound high k dielectric material is present in a concentration between about 30 atomic % and about 80 atomic and more preferably between about 40 atomic % and about 60 atomic %. In some embodiments, the compound high k dielectric material comprises an alloy of TiO2 and ZrO2 and further comprises a dopant of Al2O3. In some embodiments, the compound high k dielectric material comprises an admixture of TiO2 and HfO2 and further comprises a dopant of Al2O3.
Abstract translation:用于形成具有低漏电流和低EOT的DRAM MIM电容器堆叠的方法涉及使用复合高k电介质材料。 电介质材料还包括掺杂剂。 化合物高k介电材料的一个组分以约30原子%至约80原子之间的浓度存在,更优选约40原子%至约60原子%之间。 在一些实施方案中,化合物高k介电材料包含TiO 2和ZrO 2的合金,并且还包含Al 2 O 3的掺杂剂。 在一些实施方案中,化合物高k介电材料包含TiO 2和HfO 2的混合物,并且还包含Al 2 O 3的掺杂剂。
Abstract:
A metal oxide bilayer second electrode for a MIM DRAM capacitor is formed wherein the layer of the electrode that is in contact with the dielectric layer (i.e. bottom layer) has a desired composition and crystal structure. An example is crystalline MoO2 if the dielectric layer is TiO2 in the rutile phase. The other component of the bilayer (i.e. top layer) is a sub-oxide of the same material as the bottom layer. The top layer serves to protect the bottom layer from oxidation during subsequent PMA or other DRAM fabrication steps by reacting with any oxygen species before they can reach the bottom layer of the bilayer second electrode.
Abstract:
This disclosure provides a method of fabricating a semiconductor stack and associated device, such as a capacitor and DRAM cell. In particular, a bottom electrode has a material selected for lattice matching characteristics. This material may be created from a relatively inexpensive metal oxide which is processed to adopt a conductive, but difficult-to-produce oxide state, with specific crystalline form; to provide one example, specific materials are disclosed that are compatible with the growth of rutile phase titanium dioxide (TiO2) for use as a dielectric, thereby leading to predictable and reproducible higher dielectric constant and lower effective oxide thickness and, thus, greater part density at lower cost.