1. A circuit comprising:
a current source configured to couple to a bus line having an open-collector or open-drain current driver and a pull-up resistor;
a first switch configurable to couple the current source to the bus line during a first portion of a rise time of bus line voltage and for disconnecting the current source from the bus line during a second portion of the rise time of the bus line voltage;
a second switch configurable to pull-down or release the bus line voltage; and
a switch signal generator coupled to the first and second switches and configured for configuring the first and second switches during the first and second portions of rise time.
2. The circuit of claim 1, wherein the bus line is compliant with inter-integrated circuit (I2C) bus protocol.
3. The circuit of claim 1, where the first and second switches are transistors that are biased to behave as switches.
4. A method comprising:
receiving a signal to release a bus line having an open-collector or open-drain current driver and a pull-up resistor;
releasing the bus line;
coupling a current source to the bus line during a first portion of a rise time of the bus line voltage; and
decoupling the current source from the bus line during a second portion of the rise time of the bus line voltage, where the second portion of rise time occurs after the first portion of rise time.
5. The method of claim 4, further comprising:
configuring a first switch to release the bus line; and
configuring a second switch to couple and decouple the current source to and from the bus line.
6. The method of claim 5, where the first and second switches are transistors that are biased to behave as switches.
7. The circuit of claim 1, wherein the bus line is compliant with inter-integrated circuit (I2C) bus protocol.
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 barrier coating solution for a photoresist imaged with immersion lithography, where the barrier coating comprises an alkyl alcohol solvent and a polymer comprising an ionizable group, further where pKa of the ionizable group ranges from about \u22129 to about 11, and further where the barrier coating can be removed in an aqueous alkaline solution and the barrier coating has a dissolution rate of less than 1% of the film thickness while immersed for 30 seconds in water.
2. The composition of claim 1, where the polymer has the structure
where, R is the polymeric backbone, W is a spacer group, ZH is the ionizable group, and t=0-5.
3. The composition of claim 2, where R is selected from a multicyclic polymeric backbone, a monocyclic backbone, a linear aliphatic backbone, a branched aliphatic backbone, an aromatic backbone, a fluorinated alkyl backbone and mixtures thereof.
4. The composition of claim 2, where ZH is selected from \u2014C(CnF2n+1)2OH (n=1-8), \u2014PhOH, (SO2)2 NH, (SO2)3CH, (CO)2H, SO3H, PO3H and CO2H.
5. The composition of claim 1, where the solvent is selected from an alkyl alcohol with the structure HOCnH2n+1, where n is between 3 and 7.
6. The composition of claim 1, where the solvent further comprises an n-alkane solvent with the structure CnH2n+2, where n is between 3 and 7.
7. The composition of claim 1, further comprising a photoactive compound.
8. A process for imaging a photoresist comprising the steps of,
a) forming a coating of a photoresist on a substrate;
b) forming a barrier coating over the photoresist from a barrier coating solution of claim 1;
c) imagewise exposing the photoresist and the barrier coating using immersion lithography, further where the immersion lithography comprises an immersion liquid between the barrier coating and exposure equipment; and
d) developing the coatings with an aqueous alkaline solution.
9. The process of claim 1, where the barrier coating is insoluble in the immersion liquid.
10. The process of claim 1, where the immersion liquid comprises water.
11. The process of claim 1, where the barrier coating is soluble in an aqueous alkaline solution.
12. The process of claim 1, where the photoresist is sensitive to exposure wavelength between 150 nm and 450 nm.
13. The process of claim 1, where the barrier coating further comprises a carboxylate solvent and a polymer comprising an ionizable group.
14. The process of claim 13, where the polymer has the structure
where, R is a polymeric backbone, W is a spacer group, ZH is the ionizable group, and t=0-5.
15. The process of claim 14, where R is selected from a multicyclic polymeric backbone, a monocyclic backbone, a linear aliphatic backbone, a branched aliphatic backbone, an aromatic backbone, a fluorinated alkyl backbone, and mixtures thereof.
16. The process of claim 14, where ZH is selected from \u2014C(CnF2n+1)2OH (n=1-8), \u2014PhOH, (SO2)2 NH, (SO2)3CH, (CO)2NH, SO3H, PO3H and CO2H.
17. The process of claim 13, where the barrier coating further comprises a photoactive compound.
18. The process of claim 13, where the alkyl alcohol has the structure HOCnH2n+1, where n is between 3 and 12.
19. The process of claim 13, where the solvent further comprises an n-alkane solvent with the structure CnH2n+2, where n is between 3 and 12.
20. The process of claim 1, where the aqueous alkaline solution comprises tetramethyl ammonium hydroxide.
21. A process for imaging a deep UV photoresist to prevent environmental base contamination comprising the steps of,
a) forming a coating of a photoresist on a substrate;
b) forming a barrier coating over the photoresist from a barrier coating solution of claim 5;
c) imagewise exposing the photoresist and the barrier coating in a gaseous environment; and,
d) developing the coatings with an aqueous alkaline solution.
22. The process of claim 21 where the polymer has a pKa of less than 9.
23. The process of claim 21 where the barrier coating solution further comprises a photoactive compound.
24. The process of claim 21 where the exposure step is in air.
25. The process of claim 21 where the exposure is at 193 nm or 157 nm.
26. The process of claim 21 where the aqueous alkaline solution comprises tetramethyl ammonium hydroxide.
27. The process of claim 21, where the solvent further comprises, an alkane or a carboxylate.