摘要:
A semiconductor layer having a channel formation region provided between a pair of impurity regions spaced from each other is provided, and a first insulating layer a floating gate, a second insulating layer, and a control gate are provided above the semiconductor layer. The semiconductor material forming the floating gate preferably has a band gap smaller than that of the semiconductor layer. The band gap of a channel formation region in the semiconductor material forming the floating gate is preferably smaller than that of the semiconductor layer by 0.1 eV or more.
摘要:
A nonvolatile semiconductor memory device which is superior in writing property and charge holding property, including a semiconductor substrate in which a channel formation region is formed between a pair of impurity regions, and a first insulating layer, a floating gate, a second insulating layer, and a control gate over the semiconductor substrate. The floating gate includes at least two layers. It is preferable that a band gap of a first layer included in the floating gate, which is in contact with the first insulating layer, be smaller than that of the semiconductor substrate. For example, it is preferable that the band gap of the semiconductor material for forming the floating gate be smaller than that of the channel formation region in the semiconductor substrate by 0.1 eV or more. This is because, by lowering the bottom energy level of a conduction band of the floating gate electrode than that of the channel formation region in the semiconductor substrate, a carrier injecting property and a charge holding property are improved.
摘要:
It is an object of the present invention to provide a nonvolatile semiconductor memory device which has superior writing characteristics and electric charge retention characteristics. In addition, it is an object of the present invention to provide a nonvolatile semiconductor memory device in which a writing voltage can be reduced. The nonvolatile semiconductor memory device includes a semiconductor region with a channel formation region formed between a pair of impurity regions which are formed to be apart from each other; and a first insulating layer, a charge accumulation layer, a second insulating layer, and a control gate are formed in a location which is a top layer portion of the semiconductor region and which roughly overlaps with the channel formation region. The charge accumulation layer is insulative and is formed as a layer in which electric charge can be trapped.
摘要:
A nonvolatile semiconductor memory device which is superior in writing property and charge holding property, including a semiconductor substrate in which a channel formation region is formed between a pair of impurity regions, and a first insulating layer, a floating gate, a second insulating layer, and a control gate over the semiconductor substrate. The floating gate includes at least two layers. It is preferable that a band gap of a first layer included in the floating gate, which is in contact with the first insulating layer, be smaller than that of the semiconductor substrate. For example, it is preferable that the band gap of the semiconductor material for forming the floating gate be smaller than that of the channel formation region in the semiconductor substrate by 0.1 eV or more. This is because, by lowering the bottom energy level of a conduction band of the floating gate electrode than that of the channel formation region in the semiconductor substrate, a carrier injecting property and a charge holding property are improved.
摘要:
It is an object to provide a nonvolatile semiconductor memory device having excellent writing property and charge-retention property. A semiconductor layer including a channel forming region between a pair of impurity regions which are formed to be apart from each other is provided. In an upper layer portion thereof, a first insulating layer, a floating gate, a second insulating layer, and a control gate are provided. The floating gate has at least a two-layer structure, and a first layer in contact with the first insulating layer preferably has a band gap smaller than that of the semiconductor layer. Furthermore, by setting an energy level at the bottom of the conduction band of the floating gate lower than that of the channel forming region of the semiconductor layer, injectability of carriers and a charge-retention property can be improved.
摘要:
An object is to provide a nonvolatile semiconductor memory device which is superior in writing property and charge holding property. A semiconductor substrate in which a channel formation region is formed between a pair of impurity regions is provided, and a first insulating layer, a floating gate electrode, a second insulating layer, and a control gate electrode are provided over the semiconductor substrate. The floating gate electrode includes at least two layers. It is preferable that a band gap of a first floating gate electrode, which is in contact with the first insulating layer, be smaller than that of the semiconductor substrate. It is also preferable that a second floating gate electrode be formed of a metal material, an alloy material, or a metal compound material. This is because, by lowering the bottom energy level of a conduction band of the floating gate electrode than that of the channel formation region in the semiconductor substrate, a carrier injecting property and a charge holding property can be improved.
摘要:
It is an object to provide a nonvolatile semiconductor memory device with an excellent writing property and charge-retention property. A semiconductor layer including a channel forming region between a pair of impurity regions which are formed to be apart from each other is provided. In an upper layer portion thereof, a first insulating layer, a floating gate electrode, a second insulating layer, and a control gate electrode are provided. The floating gate has at least a two-layer structure, and a first layer being in contact with the first insulating layer preferably has a band gap smaller than that of the semiconductor layer. The stability of the first layer is improved by formation of a second layer of the floating gate electrode using a metal, an alloy, or a metal compound material. Such a structure of the floating gate electrode can improve injectability of carriers in writing and a charge-retention property.
摘要:
A nonvolatile semiconductor memory device which is superior in writing and charge holding properties, including a semiconductor substrate in which a channel formation region is formed between a pair of impurity regions formed with an interval, and a first insulating layer, a floating gate, a second insulating layer, and a control gate over an upper layer portion of the semiconductor substrate. It is preferable that a band gap of a semiconductor material forming the floating gate be smaller than that of the semiconductor substrate. For example, it is preferable that the band gap of the semiconductor material forming the floating gate be smaller than that of the channel formation region in the semiconductor substrate by 0.1 eV or more. This is because, by decreasing the bottom energy level of a conduction band of the floating gate electrode to be lower than that of the channel formation region in the semiconductor substrate, carrier injecting and charge holding properties are improved.
摘要:
It is an object to provide a nonvolatile semiconductor memory device having excellent writing property and charge-retention property. A semiconductor layer including a channel forming region between a pair of impurity regions which are formed to be apart from each other is provided. In an upper layer portion thereof, a first insulating layer, a floating gate, a second insulating layer, and a control gate are provided. The floating gate has at least a two-layer structure, and a first layer in contact with the first insulating layer preferably has a band gap smaller than that of the semiconductor layer. Furthermore, by setting an energy level at the bottom of the conduction band of the floating gate lower than that of the channel forming region of the semiconductor layer, injectability of carriers and a charge-retention property can be improved.
摘要:
An object is to provide a nonvolatile semiconductor memory device which is superior in writing property and charge holding property. A semiconductor substrate in which a channel formation region is formed between a pair of impurity regions is provided, and a first insulating layer, a floating gate electrode, a second insulating layer, and a control gate electrode are provided over the semiconductor substrate. The floating gate electrode includes at least two layers. It is preferable that a band gap of a first floating gate electrode, which is in contact with the first insulating layer, be smaller than that of the semiconductor substrate. It is also preferable that a second floating gate electrode be formed of a metal material, an alloy material, or a metal compound material. This is because, by lowering the bottom energy level of a conduction band of the floating gate electrode than that of the channel formation region in the semiconductor substrate, a carrier injecting property and a charge holding property can be improved.