1. An image forming apparatus for electrophotographically forming an image, comprising:
an image forming section for printing the toner image on a recording medium to form an image, the image forming section including a photoreceptor having a photosensitive layer for forming an electrostatic latent image on a surface thereof, and a developing device including a developing roller for supplying a toner to the electrostatic latent image on the surface of the photoreceptor to form a toner image, and a developer tank for storing a two-component developer containing a toner;
a toner concentration detecting section for detecting a toner concentration in the developer tank;
a printing speed switching section for switching a speed of printing an image formed by the image forming section;
a toner concentration calculating section for calculating a toner concentration in the developer tank from a detection result by the toner concentration detecting section, according to the speed of printing an image;
a toner replenishment control section for replenishing the toner into the developer tank according to a calculation result by the toner concentration calculating section; and
a sensitivity switching section for switching a detecting sensitivity of the toner concentration detecting section depending on the print speed of an image.
2. The image forming apparatus of claim 1, wherein the image forming section forms a monochrome image or a color image.
3. The image forming apparatus of claim 1, wherein the printing speed switching section carries out switching of speed of printing among speed of printing a monochrome image, speed of printing a color image and speed of printing on cardboard.
4. The image forming apparatus of claim 1, further comprising a toner concentration correcting section for correcting the calculation result by the toner concentration calculating section.
5. The image forming apparatus of claim 4, wherein the toner concentration correcting section corrects the calculation result by the toner concentration calculating section, based on a data table showing a relationship between detecting sensitivities of the toner concentration detecting section and correction amounts in a correction parameter.
6. The image forming apparatus of claim 5, wherein the correction parameter is based on one or two selected from a decreasing amount of a photosensitive layer on a photoreceptor, a relative humidity inside the image forming apparatus and a correction value of toner concentration obtained by process control.
7. The image forming apparatus of claim 6, further comprising:
a rotation distance accumulating section for accumulating a total rotation distance since the developing roller has been started to be used; and
a layer decreasing amount calculating section for calculating a decreasing amount of a photosensitive layer on a photoreceptor, according to an accumulation result by the rotation distance accumulating section,
wherein the toner concentration correcting section corrects the detection result by the toner concentration detecting section according to a calculation result by the layer decreasing amount calculating section.
8. The image forming apparatus of claim 6, further comprising a humidity detecting section for detecting a relative humidity therein,
wherein the toner concentration correcting section corrects the detection result by the toner concentration detecting section according to a detection result by the humidity detecting section.
9. The image forming apparatus of claim 6, further comprising:
a patch forming section for controlling the image forming section so as to form a plurality of toner patches on the photoreceptor of which the toner concentrations are continuously changing; and
a patch concentration detecting section for detecting patch concentrations which are toner concentrations of the plurality of toner patches formed on the photoreceptor,
wherein the toner concentration correcting section corrects the detection result by the toner concentration detecting section according to a detection result by the patch concentration detecting section.
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 method of forming side spacers upwardly extending from a substrate, comprising:
providing a template constituted by a photoresist formed on and in contact with an etch-selective layer laminated on a substrate, said photoresist having footing at a base of the photoresist, said etch-selective layer having a substantially lower etch rate than that of the photoresist;
anisotropically etching the template in a thickness direction with an oxygen-containing plasma to remove the footing of the photoresist and an exposed portion of the underlying layer;
depositing a spacer film on the template by atomic layer deposition (ALD); and
forming side spacers using the spacer film by etching.
2. The method according to claim 1, wherein the side spacers are for spacer-defined double patterning (SDDP).
3. The method according to claim 1, wherein the etch-selective layer has a substantially higher etch rate than that of the side spacers.
4. The method according to claim 1, wherein the etch-selective layer is constituted by an organic bottom antireflective coating (BARC) formed from a carbonsilicon-containing compound having a ratio of (number of C, H, and O atoms in total)(number of C atoms-number of O atoms) which is no more than 5.
5. The method according to claim 1, wherein the etch-selective layer is constituted by an organic bottom antireflective coating (BARC) having an etch selectivity substantially equivalent to that of a SiN film.
6. The method according to claim 1, wherein the etch-selective layer is constituted by an inorganic silicon- or carbon-containing layer as an antireflective coating (ARC) and a nitrogen-free oxide layer laminated on the inorganic silicon- or carbon-containing layer.
7. The method according to claim 1, further comprising etching the photoresist of the template to trim the photoresist prior to the anisotropical etching, wherein the etch-selective layer has a substantial resistance to the trimming, and substantially no footing of the photoresist remains.
8. The method according to claim 1, wherein the anisotropical etching and the deposition of the spacer film are conducted continuously in the same reactor.
9. The method according to claim 1, wherein the spacer film is constituted by SiO2 or TiO.
10. The method according to claim 1, wherein an underlying layer formed underneath the etch-selective layer is constituted by amorphous carbon.
11. The method according to claim 1, wherein the etch-selective layer is constituted by a Si-rich organic bottom antireflective coating (BARC), and the anisotropical etching comprises trimming the photoresist and removing the footing by an oxygen-containing plasma, and then etching the Si-rich BARC by a fluorine-containing oxygen plasma.