US 5,097,291 A · Energy amount control device

Abstract

An energy amount control device having a pulse energy generating source which produces pulse energy with a predetermined range of energy fluctuations per oscillation, and adjusting voltage applied to the energy generating source to thereby control an energy amount of the pulse energy, the energy amount control device comprising a storage unit for storing information about the relation between predetermined voltage to produce pulse energy in the energy generating source and an energy amount of the pulse energy emitted from the energy generating source under the predetermined voltage; an energy amount measuring unit for detecting the energy amount of the pulse energy actually emitted from the energy generating source; an arithmetic unit for updating the information stored in the storage unit at predetermined timing based on the predetermined voltage to produce the pulse energy in the energy generating source and the energy amount detected by the energy amount measuring unit; and decision unit for determining the predetermined voltage corresponding to the energy amount of the pulse energy to be next emitted, based on the information updated by the arithmetic unit.

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Claims17

Dependent claims

An energy amount control device having a pulse energy generating source which produces pulse energy with a predetermined range of energy fluctuations per oscillation, and adjusting voltage applied to said energy generating source to thereby control an energy amount of the pulse energy, said energy amount control device comprising:

storage means for storing information about the relation between predetermined voltage to produce pulse energy in said energy generating source and an energy amount of the pulse energy emitted from said energy generating source under said predetermined voltage;
energy amount measuring means for detecting the energy amount of the pulse energy actually emitted from said energy generating source;
arithmetic means for updating said information stored in said storage means at predetermined timing based on said predetermined voltage to produce the pulse energy in said energy generating source and the energy amount detected by said energy amount measuring means;
and
decision means for determining said predetermined voltage corresponding to the energy amount of the pulse energy to be next emitted, based on the information updated by said arithmetic means.

2 more elements

An exposure apparatus comprising a laser light source which requires at least partial gas replacement or gas injection and emits a coherent pulse beam with a predetermined range of energy fluctuations per oscillation, and means for adjusting voltage applied to said laser light source, wherein the plural pulse beams controlled by said adjusting means to a predetermined energy amount is irradiated to a mask to expose a pattern formed on said mask onto a sensitive substrate with a predetermined exposure amount, said exposure apparatus further comprising:

first control means for outputting signals indicative of whether either one of said partial gas replacement and gas injection of said laser light source is required or not, depending on an exposure state of said sensitive substrate;
second control means for outputting signals indicative of whether either one of said partial gas replacement or gas injection is required or not, depending on an oscillation state of said laser light source, and implementing either one of said partial gas replacement and gas injection after detecting the time at which either one of said partial gas replacement or gas injection of said laser light source is to be performed, based on the signals generated by said second control means and the signals applied from said first control means;
storage means for storing information about the relation between the applied voltage of said laser light source and the energy amount of pulse beam emitted from said laser light source on said mask or sensitive substrate under said applied voltage;
energy amount measuring means for detecting the energy amount of the pulse beam actually emitted from said laser light source on said mask or sensitive substrate;
arithmetic means for updating said information stored in said storage means at predetermined timing based on the applied voltage of said laser light source and the energy amount detected by said energy amount measuring means;
and
decision means for determining the applied voltage of said laser light source corresponding to the energy amount of the pulse beam to be next emitted, based on said updated information.

4 more elements

An exposure apparatus comprising a laser light source which requires at least partial gas replacement or gas injection and emits a coherent pulse beam with a predetermined range of energy fluctuations per oscillation, and means for adjusting voltage applied to said laser light source, wherein the plural pulse beams controlled by said adjusting means to a predetermined energy amount is irradiated to a mask to expose a pattern formed on said mask onto a sensitive substrate with a predetermined exposure amount, said exposure apparatus further comprising:

first control means for outputting signals indicative of whether either one of said partial gas replacement and gas injection of said laser light source is required or not, depending on an exposure state of said sensitive substrate;
second control means for outputting signals indicative of whether either one of said partial gas replacement or gas injection is required or not, depending on an oscillation state of said laser light source, and implementing either one of said partial gas replacement and gas injection after detecting the time at which either one of said partial gas replacement or gas injection of said laser light source is to be performed, based on the signals generated by said second control means and the signals applied from said first control means;
charged voltage measuring means for detecting charged voltage of said laser light source;
storage means for storing information about the relation between the charged voltage at the time of pulse oscillation in said laser light source and the energy amount of the pulse beam emitted from said laser light source at least on either one of said mask or sensitive substrate under said charged voltage;
energy amount measuring means for detecting the energy amount of the pulse beam actually emitted from said laser light source on said mask or sensitive substrate;
arithmetic means for updating said information stored in said storage means at predetermined timing based on the results measured by said charged voltage measuring means and said energy amount measuring means;
and
decision means for determining the applied voltage of said laser light source corresponding to the energy amount of the pulse beam to be next emitted, based on said updated information.

5 more elements

Dependencies are inferred from the claim text.

Description23,632 words

Summary2,491 words

#1. Field of the Invention

#The present invention relates to control of a total energy amount irradiated to a sensitive subject, and more particularly to control of a total irradiated energy amount in the case where the energy amount from an energy generating source of pulse oscillation type is changed over time. The present invention relates to, for example, an energy amount control device suitable for exposure amount control in an exposure apparatus using a pulse laser like an excimer laser as light for exposure.

#2. Related Background Art

Brief description of the drawings15 figures

#FIG. 1 is a block diagram showing the schematic configuration of an energy amount control device according to a first embodiment of the present invention;

#FIG. 2 is a graph showing one example of the relation between voltage applied to an energy generating source and an output power (pulse energy) under that applied voltage;

#FIG. 3 is a flowchart showing one example of operation of the energy amount control device according to the first embodiment shown in FIG. 1;

Detailed description20,759 words

#FIG. 1 is a block diagram showing the schematic configuration of an energy amount control device according to a first embodiment of the present invention. For the sake of the simplest basic configuration, the illustrated embodiment is arranged to irradiate pulse energy radiated from a pulse oscillation type energy generating source 1 to an irradiated object 3 in accordance with preset oscillation conditions input from an input/output (I/O) device 8.

#In FIG. 1, an applied voltage control portion 11 serves to control high discharge voltage (corresponding to applied voltage) of the pulse oscillation type energy generating source 1. Thus, the applied voltage control portion 11 provides the applied voltage, corresponding to the energy amount of the pulse energy to be next irradiated, to the energy generating source 1 for adjusting the energy amount per pulse. A trigger control portion 10 delivers an external trigger pulse to the energy generating source 1 and controls its oscillation (number of pulses, oscillation interval, etc.) after a preset charging time necessary for the energy generating source 1 has elapsed. The trigger control portion 10 and the applied voltage control portion 11 are both operated upon predetermined commands outputted from a main control system 9 (later described). The pulse energy radiated from the energy generating source 1 may be, for example, a coherent laser beam, an incoherent pulse beam, or pulse energy such as an electron ray other than light.

#An energy beam EB emitted from the energy generating source 1 is divided into two beams by a beam splitter 2. A large part of the energy beam EB passes through the beam splitter 2 to be irradiated to the irradiated object 3. On the other hand, a small part of the energy beam EB reflected by the beam splitter 2 enters an energy monitor element 4 (e.g., a pyroelectric type power meter or PIN photodiode in the case of using an excimer laser). The energy monitor element 4 outputs a signal precisely depending on an energy amount of the energy beam EB per pulse. The output signal from the monitor element 4 is inputted to an energy amount monitoring portion 5 for conversion into the energy amount per pulse. Thus, the monitor element 4 and the energy amount monitoring portion 5 jointly constitute energy amount measuring means in the present invention to measure an energy amount of the energy beam which is associated in a predetermined relation with the energy beam irradiated to the irradiated object 3, i.e., which is uniquely defined by an optical capability of the beam splitter 2.

Energy amount control device

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Energy amount control device

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Life of this patent

Abstract

Drawings

Drawings

Claims17

Description23,632 words

Drawings

Classification4 codes

Life of this patent

Description23,632 words