# US 2017/0256307 A1 · Semiconductor device and method for driving semiconductor device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0256307 A1 - Document ID: US20170256307A1 - Status: Published application - Kind: A1 - Application number: 15/603,570 - Filed: 2017-05-24 - Published: 2017-09-07 - Earliest claimed: 2013-03-22 - Assignees: Semiconductor Energy Laboratory Co., Ltd. - Applicants: Semiconductor Energy Laboratory Co., Ltd. - Inventors: Tatsuya ONUKI - Web page: https://patentgrep.com/patent/US20170256307A1 ## CPC - G11C 11/565: {using capacitive charge storage elements} - G11C 11/403: with charge regeneration common to a multiplicity of memory cells, i.e. external refresh - G11C 11/4076: Timing circuits (for regeneration management G11C11/406) - G11C 11/4091: Sense or sense/refresh amplifiers, or associated sense circuitry, e.g. for coupled bit-line precharging, equalising or isolating - G11C: STATIC STORES (semiconductor memory devices H10B) ## Abstract To provide a semiconductor device which can write and read a desired potential. The semiconductor device includes a first transistor (Tr), a second Tr, and a capacitor. In the semiconductor device, operation of writing data is performed by a first step and a second step. In the first step, a low voltage is applied to a bit line and a first wiring to turn on the first Tr and the second Tr. In the second step, a first voltage is applied to the first wiring, and application of the low voltage to the bit line is stopped. Operation of reading the data is performed by a third step and a fourth step. In the third step, a high voltage is applied to the first wiring. In the fourth step, application of the high voltage to the first wiring is stopped, and a low voltage is applied to a capacitor line. ## Claims ### Claim 1 A method for driving a semiconductor device including a first transistor whose channel region includes an oxide semiconductor, a second transistor, and a capacitor whose one electrode electrically connected to one of a source and a drain of the first transistor and a gate of the second transistor, the method comprising: applying a low voltage to a bit line and a first wiring, applying a high voltage to a word line to turn on the first transistor, and applying a low voltage to a capacitor line, thereby turning on the second transistor, wherein: the word line is electrically connected to a gate of the first transistor, the first wiring is electrically connected to one of a source and a drain of the second transistor, the bit line is electrically connected to the other of the source and the drain of the first transistor and the other of the source and the drain of the second transistor, and the capacitor line is electrically connected to the other electrode of the capacitor; applying a first voltage to the first wiring and stopping the application of the low voltage to the bit line so that a voltage corresponding to the first voltage is applied to the gate of the second transistor from the first wiring through the source and the drain of the second transistor, the bit line, and the source and the drain of the first transistor; applying a low voltage to the word line to turn off the first transistor, applying a low voltage to the bit line and the first wiring, and applying a high voltage to the capacitor line to turn off the second transistor; applying a high voltage to the first wiring; and stopping the application of the high voltage to the first wiring, and applying a low voltage to the capacitor line so that a voltage of the first wiring changes from the high voltage to the first voltage. ### Claim 2 (depends on 1) The method according to claim 1, wherein a channel region of the second transistor includes silicon. ### Claim 3 (depends on 1) The method according to claim 1, further comprising converting a potential of the first wiring into digital value and outputting the digital value outside, wherein an A/D converter electrically connected to the first wiring converts the potential of the first wiring. ### Claim 4 A method for driving a semiconductor device including a first transistor whose channel region includes an oxide semiconductor, a second transistor, a third transistor, and a capacitor whose one electrode electrically connected to one of a source and a drain of the first transistor and a gate of the second transistor, the method comprising: applying a low voltage to a bit line and a first wiring, applying a high voltage to a first word line to turn on the first transistor, applying the low voltage of the bit line to the gate of the second transistor to turn on the second transistor, and applying a low voltage to a second word line to turn on the third transistor, wherein: the first word line is electrically connected to a gate of the first transistor, the second word line is electrically connected to a gate of the third transistor, the first wiring is electrically connected to one of a source and a drain of the second transistor one of a source and a drain of the third transistor is electrically connected to the other of the source and the drain of the second transistor, the bit line is electrically connected to the other of the source and the drain of the first transistor and the other of the source and the drain of the third transistor, and a low voltage is applied to the other electrode of the capacitor; applying a first voltage to the first wiring, and stopping the application of the low voltage to the bit line so that a voltage corresponding to the first voltage is applied to the gate of the second transistor from the first wiring through the source and the drain of the second transistor, the source and the drain of the third transistor, the bit line, and the source and the drain of the first transistor; applying a low voltage to the first word line to turn off the first transistor, applying a low voltage to the bit line and the first wiring, and applying a high voltage to the second word line to turn off the third transistor; applying a high voltage to the first wiring; and stopping the application of the high voltage to the first wiring, and applying a low voltage to the second word line to turn on the third transistor so that a voltage of the first wiring changes from the high voltage to the first voltage. ### Claim 5 (depends on 4) The method according to claim 4, wherein a channel region of the second transistor includes silicon. ### Claim 6 (depends on 4) The method according to claim 4, wherein a channel region of the second transistor includes silicon, and wherein a channel region of the third transistor includes silicon. ### Claim 7 (depends on 4) The method according to claim 4, further comprising converting a potential of the first wiring into a digital value and outputting the digital value outside, wherein an A/D converter electrically connected to the first wiring converts the potential of the first wiring. ### Claim 8 A method for driving a semiconductor device including a first transistor whose channel region includes an oxide semiconductor, a second transistor, and a capacitor whose one electrode electrically connected to one of a source and a drain of the first transistor and a gate of the second transistor, the method comprising: applying a high voltage to a bit line and a first wiring, applying a high voltage to a word line to turn on the first transistor, and applying a high voltage to a capacitor line, thereby turning on the second transistor, wherein: the word line is electrically connected to a gate of the first transistor, the first wiring is electrically connected to one of a source and a drain of the second transistor, the bit line is electrically connected to the other of the source and the drain of the first transistor and the other of the source and the drain of the second transistor, and the capacitor line is electrically connected to the other electrode of the capacitor; applying a first voltage to the first wiring and stopping application of the high voltage to the bit line so that a voltage corresponding to the first voltage is applied to the gate of the second transistor from the first wiring through the source and the drain of the second transistor, the bit line, and the source and the drain of the first transistor; applying a low voltage to the word line to turn off the first transistor, applying a high voltage to the bit line and the first wiring, and applying a low voltage to the capacitor line to turn off the second transistor; applying a low voltage to the first wiring; and stopping the application of the low voltage to the first wiring, and applying a high voltage to the capacitor line so that a voltage of the first wiring changes from the low voltage to the first voltage. ### Claim 9 (depends on 8) The method according to claim 8, wherein a channel region of the second transistor includes silicon. ### Claim 10 (depends on 8) The method according to claim 8, further comprising converting a potential of the first wiring into a digital value and outputting the digital value outside, wherein an A/D converter electrically connected to the first wiring converts the potential of the first wiring. ### Claim 11 A method for driving a semiconductor device including a first transistor whose channel region includes an oxide semiconductor, a second transistor, a third transistor, and a capacitor whose one electrode electrically connected to one of a source and a drain of the first transistor and a gate of the second transistor, the method comprising: applying a high voltage to a bit line and a first wiring, applying a high voltage to a first word line to turn on the first transistor, applying the high voltage of the bit line to the gate of the second transistor to turn on the second transistor, and applying a high voltage to a second word line to turn on the third transistor, wherein: the first word line is electrically connected to a gate of the first transistor, the second word line is electrically connected to a gate of the third transistor, the first wiring is electrically connected to one of a source and a drain of the second transistor one of a source and a drain of the third transistor is electrically connected to the other of the source and the drain of the second transistor, the bit line is electrically connected to the other of the source and the drain of the first transistor and the other of the source and the drain of the third transistor, and a low voltage is applied to the other electrode of the capacitor; applying a first voltage to the first wiring, and stopping the application of the high voltage to the bit line so that a voltage corresponding to the first voltage is applied to the gate of the second transistor from the first wiring through the source and the drain of the second transistor, the source and the drain of the third transistor, the bit line, and the source and the drain of the first transistor; applying a low voltage to the first word line to turn off the first transistor, applying a high voltage to the bit line and the first wiring, and applying a low voltage to the second word line to turn off the third transistor; applying a low voltage to the first wiring; and stopping the application of the low voltage to the first wiring, and applying a high voltage to the second word line to turn on the third transistor so that a voltage of the first wiring changes from the high voltage to the first voltage. ### Claim 12 (depends on 11) The method according to claim 11, wherein a channel region of the second transistor includes silicon. ### Claim 13 (depends on 11) The method according to claim 11, wherein a channel region of the second transistor includes silicon, and wherein a channel region of the third transistor includes silicon. ### Claim 14 (depends on 11) The method according to claim 11, further comprising converting a potential of the first wiring into a digital value and outputting the digital value outside, wherein an A/D converter electrically connected to the first wiring converts the potential of the first wiring.