Abstract:
A semiconductor device in which MRAM is formed in a wiring layer A contained in a multilayered wiring layer, the MRAM having at least two first magnetization pinning layers in contact with a first wiring formed in a wiring layer and insulated from each other, a free magnetization layer overlapping the two first magnetization pinning layers in a plan view, and connected with the first magnetization pinning layers, a non-magnetic layer situated over the free magnetization layer, and a second magnetization pinning layer situated over the non-magnetic layer.
Abstract:
A resistance change element includes first and second electrodes spaced apart from each other, a metal material layer adjacent to the first electrode, an oxide layer adjacent to each of the metal material layer and the first electrode, and a resistance change layer disposed continuously between the second and first electrodes and between the second electrode and the oxide layer. The resistance change layer is made of a metal oxide. The metal material layer is made of a metal or a metal compound. The oxide layer is made of an oxide of the material forming the metal material layer. The first electrode is made of ruthenium, ruthenium oxide, iridium, iridium oxide, platinum, gold, or copper. A free energy of oxide formation of the oxide forming the oxide layer is higher than a free energy of oxide formation of the oxide forming the resistance change layer.
Abstract:
Included are memory cells each including a resistance change element and a control circuit. The circuit performs an On writing process for applying, to the memory cell, an On writing pulse for the cell to be in a resistance state where a resistance value of the resistance change element is lower than a first reference value and an Off writing process for applying an Off writing pulse with an opposite polarity to the On writing pulse for a high resistance state with a second reference value or greater. The circuit applies, in the On writing process, a trial pulse having the same polarity as that of the On writing pulse and having the pulse width shorter than that of the On writing pulse and a reset pulse having the same polarity as that of the On writing pulse, in this order before applying the On writing pulse to the cell.
Abstract:
A semiconductor device has a resistance change element that is high in the holding resistance of a low resistance (On) state while securing a memory window. In a resistance random access memory including selection transistors and resistance change elements coupled in series to the selection transistors, the resistance change element uses a lower electrode that applies a positive voltage when being transited to a high resistance (Off) state, an upper electrode that faces the lower electrode, and a resistance change layer that is sandwiched between the lower electrode and the upper electrode and that uses an oxide of transition metal. The resistance change layer contains nitrogen. The concentration of nitrogen on the lower electrode side is higher than that on the upper electrode side. The nitrogen in the resistance change layer exhibits a concentration gradient continuously declined from the lower electrode side to the upper electrode side.
Abstract:
Provided is a semiconductor memory device (resistance random access memory element) improved in properties. A Ru film is formed as a film of a lower electrode by sputtering, and a Ta film is formed thereonto by sputtering. Next, the Ta film is oxidized with plasma to oxidize the Ta film. In this way, a compound Ta2O5 is produced and further Ru is diffused into the compound to form a layer (variable resistance layer) in which Ru is diffused into the compound Ta2O5. Such an incorporation of a metal (such as Ru) into a transition metal oxide TMO (such as Ta2O5) makes it possible to form electron conductive paths additional to filaments to lower the filaments in density and thickness. Thus, the memory element can be restrained from undergoing OFF-fixation, by which the element is not easily lowered in resistance, to be improved in ON-properties.
Abstract translation:提供了一种改进了性能的半导体存储器件(电阻随机存取存储元件)。 通过溅射形成作为下电极的膜的Ru膜,并通过溅射在其上形成Ta膜。 接着,用等离子体氧化Ta膜,氧化Ta膜。 以这种方式,产生化合物Ta 2 O 5,并且进一步将Ru扩散到化合物中以形成其中Ru扩散到化合物Ta 2 O 5中的层(可变电阻层)。 金属(例如Ru)的这种引入到过渡金属氧化物TMO(例如Ta 2 O 5)中使得有可能形成除了长丝之外的电子传导路径以降低细丝的密度和厚度。 因此,可以抑制存储元件的导通性能的提高,使得元件不易于降低电阻的非固定。
Abstract:
To provide a semiconductor device having less variation in characteristics. The semiconductor device is equipped with a plug formed in an interlayer insulating film, a lower electrode provided on the plug and to be coupled to the plug, a middle layer provided on the lower electrode and made of a metal oxide, and an upper electrode provided on the middle layer. The middle layer has a layered region contiguous to the lower electrode and the upper electrode. At least a portion of the layered region does not overlap with the plug. At least a portion of the plug does not overlap with the layered region.