1. A mask pattern forming method comprising:
a resist film step of forming a resist film over a thin film;
a patterning step of processing the resist film into resist patterns having a predetermined pitch by photolithography;
a slimming step of performing slimming of the resist patterns; and
a film deposition step of forming an oxide film on the thin film and the resist patterns after an end of the slimming step in a film deposition apparatus by supplying a source gas and an oxygen radical or an oxygen-containing gas,
wherein the slimming step and the film deposition step are continuously performed in the film deposition apparatus.
2. The mask pattern forming method according to claim 1, wherein the resist film step is arranged to include a step of forming a coating on the thin film and a step of forming the resist film on the coating,
the patterning step is arranged to process the resist film into resist patterns including line parts arrayed at the predetermined pitch by photolithography,
the slimming step is arranged to perform the slimming of the resist patterns in the film deposition apparatus used to form the oxide film,
the film deposition step is arranged to form, continuously from the end of the slimming step, the oxide film on the thin film and the resist patterns in the film deposition apparatus by supplying the source gas and the oxygen radical or the oxygen-containing gas into the film deposition apparatus, and
wherein the mask pattern forming method further comprises:
an etching step of etching the oxide film after an end of the film deposition step so that the oxide film remains as side wall parts on side faces of each of the line parts of the resist patterns after the end of the slimming step;
a step of removing the resist patterns after an end of the etching step so that the side wall parts of the oxide film remain on the coating; and
a step of etching the coating by using the side wall parts of the oxide film as a mask so that mask patterns including the side wall parts and the coating are formed on the thin film.
3. The mask pattern forming method according to claim 1, wherein the resist film step is arranged to include a step of forming a coating on the thin film and a step of forming the resist film on the coating,
the patterning step is arranged as a first patterning step of processing the resist film into first resist patterns having a first pitch by photolithography,
the slimming step is arranged as a first slimming step of performing slimming of the first resist patterns in the film deposition apparatus used to form the oxide film,
the film deposition step is arranged to form, continuously from an end of the first slimming step, the oxide film on the thin film and the first resist patterns in the film deposition apparatus by supplying the source gas and the oxygen radical or the oxygen-containing gas into the film deposition apparatus, and
wherein the mask pattern forming method further comprises:
a step of forming a second resist film on the oxide film;
a second patterning step of processing the second resist film into second resist patterns having a second pitch equal to the first pitch by photolithography, the second resist patterns being shifted by half of the first pitch so that the first resist patterns and the second resist patterns are arrayed alternately;
a second slimming step of performing slimming of the second resist patterns after an end of the second patterning step; and
a step of etching the oxide film and the coating by using as a mask the first resist patterns after the end of the first slimming step and the second resist patterns after an end of the second slimming step so that mask patterns including the first resist patterns and the second resist patterns and arrayed at a pitch equal to the half of the first pitch are formed on the thin film.
4. The mask pattern forming method according to claim 1, wherein the slimming of the resist patterns in the slimming step is performed using oxygen-containing gas plasma or ozone gas.
5. The mask pattern forming method according to claim 1, wherein the oxygen radical used in the film deposition step is an oxygen-containing gas plasma.
6. The mask pattern forming method according to claim 5, wherein the oxygen-containing gas plasma contains a gas, chosen from the group consisting of O2 gas, NO gas, N2O gas, H2O gas and O3 gas, which is in a plasma state.
7. The mask pattern forming method according to claim 1, wherein the film deposition step is arranged so that the oxide film is formed within a process chamber capable of holding the source gas under a vacuum pressure, by performing alternately a source gas supply step of supplying the source gas to the process chamber and an oxygen radical supply step of supplying the oxygen radical or the oxygen-containing gas to the process chamber.
8. The mask pattern forming method according to claim 7, wherein the film deposition step is arranged to perform a remaining gas removal step of removing a remaining gas in the process chamber during an intermediate period between the source gas supply step and the oxygen radical supply step.
9. The fine pattern forming method according to claim 8, wherein the remaining gas removal step is arranged so that a purge gas is introduced into the process chamber when a pressure inside the process chamber is decreased to the vacuum pressure.
10. The mask pattern forming method according to claim 1, wherein a temperature at which the oxide film is formed in the film deposition step is below a heat-resisting temperature of the resist film.
11. The mask pattern forming method according to claim 10, wherein the temperature at which the oxide film is formed in the film deposition step is below 100 degrees C.
12. The mask pattern forming method according to claim 1, wherein the source gas contains organic silicone and the oxide film is a silicon oxide film.
13. A fine pattern forming method comprising:
a step of forming a thin film on a substrate;
a step of forming mask patterns on the thin film by performing the mask pattern forming method according to claim 1; and
a step of etching the thin film by using the mask patterns, to form thin film patterns including the thin film etched.
14. A mask pattern forming method comprising:
a step of forming a coating on a thin film;
a step of forming a resist film on the coating;
a first patterning step of processing the resist film into first resist patterns including line parts arrayed at a first pitch by photolithography;
a first slimming step of performing slimming of the first resist patterns; and
a film deposition step of forming an aluminum oxide film at room temperature on the thin film and the first resist patterns after an end of the first slimming step by supplying a source gas and an oxygen-containing gas.
15. The mask pattern forming method according to claim 14, further comprising:
an etching step of etching the aluminum oxide film so that the aluminum oxide film remains as side wall parts on side faces of each of the line parts of the first resist patterns after the end of the first slimming step;
a step of forming a wall part by removing the first resist patterns after the end of the first slimming step so that the side wall parts of the aluminum oxide film remain; and
a step of etching the coating by using the side wall parts of the aluminum oxide film as a mask so that mask patterns including the side wall parts and the coating are formed on the thin film.
16. The mask pattern forming method according to claim 14, further comprising:
a silicon oxide film deposition step of forming a silicon oxide film on the aluminum oxide film after an end of the film deposition step by supplying a source gas containing organic silicone and an oxygen radical;
an etching step of etching the silicon oxide film and the aluminum oxide film so that the silicon oxide film and the aluminum oxide film remain as side wall parts on side faces of each of the line parts of the first resist patterns after an end of the first slimming step;
a step of removing the first resist patterns after the end of the first slimming step so that the side wall parts including the silicon oxide film and the aluminum oxide film remain;
a step of etching the coating by using the side wall parts as a mask so that mask patterns including the side wall parts and the coating are formed on the thin film.
17. The mask pattern forming method according to claim 14, further comprising:
a step of forming a second resist film on the aluminum oxide film;
a second patterning step of processing the second resist film into second resist patterns having a second pitch equal to the first pitch by photolithography, the second resist patterns being shifted by half of the first pitch so that the first resist patterns and the second resist patterns are arrayed alternately;
a second slimming step of performing slimming of the second resist patterns after an end of the second patterning step; and
a step of etching the aluminum oxide film and the coating by using as a mask the first resist patterns after the end of the first slimming step and the second resist patterns after an end of the second slimming step so that mask patterns including the first resist patterns and the second resist patterns and arrayed at a pitch equal to the half of the first pitch are formed on the thin film.
18. A film deposition apparatus comprising:
a process chamber arranged to hold a vacuum pressure and to process a semiconductor substrate;
a source gas supplying unit arranged to supply a source gas to the process chamber; and
an oxygen radical supplying unit arranged to supply an oxygen radical or an oxygen-containing gas to the process chamber,
wherein the film deposition apparatus is arranged so that the source gas and the oxygen radical or the oxygen-containing gas are alternately supplied to the process chamber by the source gas supplying unit and the oxygen radical supplying unit, to form an oxide film over the semiconductor substrate on which resist patterns are formed, and
wherein the film deposition apparatus is arranged to perform, before the oxide film is formed over the semiconductor substrate on which the resist patterns are formed, slimming of the resist patterns by supplying the oxygen radical to the process chamber by the oxygen radical supplying unit.
19. The film deposition apparatus according to claim 18, wherein the film deposition apparatus is arranged so that the source gas and the oxygen radical or the oxygen-containing gas are alternately supplied to the process chamber to form an oxide film which uniformly covers side walls of each of the resist patterns on a coating formed through the thin film on the semiconductor substrate, and mask patterns including the coating and side wall parts of the oxide film covering the side walls of each of the resist patterns formed on the coating are formed on the thin film.
20. The film deposition apparatus according to claim 18, wherein the film deposition apparatus is arranged so that the source gas and the oxygen radical or the oxygen-containing gas are alternately supplied to the process chamber to form an oxide film which uniformly covers first resist patterns, formed through the thin film and a coating on the semiconductor substrate and having a first pitch, and second resist patterns having a second pitch equal to the first pitch and shifted by half of the first pitch so that the first resist patterns and the second resist patterns are arrayed alternately, and mask patterns including the first resist patterns and the second resist patterns are formed on the thin film.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A solid state imaging device comprising:
a pixel cell including an FD node to convert a charge stored in a photodiode into a signal voltage and an amplifier transistor in which a gate is connected to the FD node, a source is connected to an output signal line, and a drain is connected to a pixel-power node;
a voltage control portion including a first control transistor in which a gate sets to a first bias voltage, a source is connected to the output signal line, and a drain is connected to a first control portion-power node;
a load circuit including a current source connected directly between one end of the output signal line and a source power supply node; and
a control circuit which controls an operation to decide a reset voltage of the output signal line,
wherein the control circuit boosts the FD node by activating a first source follower circuit comprising the first control transistor and the current source before activating a second source follower circuit comprising the amplifier transistor and the current source, and sets a voltage of the output signal line when the FD node is boosted as the reset voltage.
2. The device of claim 1,
wherein the load circuit has no switch function.
3. The device of claim 1,
wherein the load circuit continues to pass a constant current during operation of pixel signal reading.
4. The device of claim 1,
wherein the voltage control portion further includes a first switch to control the first source follower circuit.
5. The device of claim 1,
wherein the voltage control portion further comprises:
a first switch to control the first source follower circuit,
a second control transistor in which a gate sets to a second bias voltage, a source is connected to the output signal line, and a drain is connected to a second control portion-power node, and
a second switch which controls a third source follower circuit comprising the second control transistor and the current source,
wherein the control circuit causes the third source follower circuit after activating the first source follower circuit and before activating the second source follower circuit.
6. The device of claim 1,
wherein the first bias voltage is variable and
the first source follower circuit is controlled by OnOff of the first control transistor.
7. The device of claim 1,
wherein the control circuit reads the signal voltage to the output signal line by transferring the charge stored in the photodiode to the FD node after sampling the reset voltage in a sample hold circuit in an AD converter,
wherein the AD converter outputs a difference between the reset voltage and the signal voltage.
8. The device of claim 1, further comprising a read transistor connected to between the photodiode and the FD node.
9. The device of claim 1, further comprising a reset transistor connected to between the FD node and the pixel-power node to reset the voltage of the FD node.
10. The device of claim 1, further comprising a row select transistor connected to between the drain of the amplifier transistor and the pixel-power node.