Photo-cathode image projection apparatus for patterning a semiconductor device

A photo-cathode image projection apparatus for projecting an image of a desired pattern on an object by a focused photoelectron beam, comprising:

• light source means for producing an optical beam;
• a photoelectron mask means disposed so as to be irradiated by the optical beam from the light source, said photoelectron mask means including a photoelectron mask patterned according to said desired pattern with a material emitting photoelectrons in response to irradiation by said optical beam;
• focusing means for focusing the photoelectrons emitted from the photoelectron mask to form a focused photoelectron beam that is focused on an object;
• acceleration electrode means disposed in the path of the photoelectron beams for accelerating the photoelectrons in the photoelectron beam;
• elongated passage means defined in said acceleration electrode means for allowing a part of the photoelectron beam to pass therethrough;
• stage means disposed for supporting the said object to that the part of the photoelectron beam passed through the elongated passage means is focused on the object;
• and
• voltage source means for applying an acceleration voltage between the photoelectron mask and the acceleration electrode means and holding said acceleration electrode means at an electrical potential level identical to the electrical potential level of the stage means, so that the object supported on the stage means is electrically shielded from said photoelectron mask by the acceleration electrode means,
• said light source means comprising means for causing the optical beam to have an elongated cross-section which extends in parallelism to the elongated passage means in the acceleration electrode means, and which cross-section has a width, measured longitudinally of the elongated passage means, that is substantially less than the corresponding width of the passage means, and which cross-section has a thickness, measured across the passage means, that is substantially less than the corresponding thickness of the passage means.

A photo-cathode image projection apparatus for projecting an image of a desired pattern on an object by a focused photoelectron beam, comprising:

• light source means for producing an optical beam;
• a photoelectron mask means disposed so as to be irradiated by the optical beam from the light source, said photoelectron mask means including a photoelectron mask patterned according to said desired pattern with a material emitting photoelectrons in response to irradiation by said optical beam;
• focusing means for focusing the photoelectrons emitted from the photoelectron mask to form a focused photoelectron beam that is focused on an object;
• acceleration electrode means disposed in the path of the photoelectron beams for accelerating the photoelectrons in the photoelectron beam;
• a single elongated passage means defined in said acceleration electrode means for allowing a part of the photoelectron beam to pass therethrough;
• stage means disposed for supporting the said object so that the part of the photoelectron beam passed through the elongated passage means is focused on the object;
• and
• voltage source means for applying an acceleration voltage between the photoelectron mask and the acceleration electrode means and holding said acceleration electrode means at an electrical potential level identical to the electrical potential level of the stage means, so that the object supported on the stage means is electrically shielded from said photoelectron mask by the acceleration electrode means,
• said light source means comprising a laser source whereby the optical beam is a laser beam, and deflecting means for deflecting the laser beam such that the laser beam scans across the photoelectron mask.

A photo-cathode image projection apparatus for projecting an image of a desired pattern on an object by a focused photoelectron beam, comprising:

• a light source means for producing an optical beam;
• photoelectron mask means disposed so as to be irradiated by the optical beam from the light source, said photoelectron mask means including a photoelectron mask patterned according to said desired pattern with a material emitting photoelectrons in response to irradiation by said optical beam;
• focused means for focusing the photoelectrons emitted from the photoelectron mask to form a focused photoelectron beam that is focused on an object;
• acceleration electrode means disposed in the path of the photoelectron beams for accelerating the photoelectrons in the photoelectron beam;
• elongated passage means defined in said acceleration electrode means for allowing a part of the photoelectron beam to pass therethrough;
• stage means disposed for supporting the said object so that the part of the photoelectron beam passed through the elongated passage means is focused on the object;
• voltage source means for applying an acceleration voltage between the photoelectron mask and the acceleration electrode means and holding said acceleration electrode means at an electrical potential level identical to the electrical potential level of the stage means, so that the object supported on the stage means is electrically shielded from said photoelectron mask by the acceleration electrode means;
• and
• means for moving said light source means and said acceleration electrode means in synchronization to each other.

A photo-cathode image projection apparatus for projecting an image of a desired pattern on an object by a focused photoelectron beam, comprising:

• light source means for producing an optical beam;
• photoelectron mask means disposed so as to be irradiated by the optical beam from the light source, said photoelectron mask means including a photoelectron mask patterned according to said desired pattern with a material emitting photoelectrons in response to irradiation by said optical beam;
• focusing means for focusing the photoelectrons emitted from the photoelectron mask to form a focused photoelectron beam that is focused on an object;
• acceleration electrode means disposed in the path of the photoelectron beams for accelerating the photoelectrons in the photoelectron beam;
• elongated passage means defined in said acceleration electrode means for allowing a part of the photoelectron beam to pass therethrough;
• stage means disposed for supporting the said object so that the part of the photoelectron beam passed through the elongated passage means is focused on the object;
• voltage source means for applying an acceleration voltage between the photoelectron mask and the acceleration electrode means and holding said acceleration electrode means at an electrical potential level identical to the electrical potential level of the stage means, so that the object supported on the stage means is electrically shielded from said photoelectron mask by the acceleration electrode means,
• said photoelectron mask means, the acceleration electrode means, and the stage means being located in an evacuated chamber, said chamber being divided into a first part including the photoelectron mask means and the acceleration electrode means and a second part including the stage means, and said first and second parts of the chamber being evacuatable separately such that the degree of vacuum in the first part is equal to or greater than the degree of vacuum in the second part.

A method of exposing an object to a photoelectron beam emitted from a photoelectron mask patterned with a material which emits photoelectron according to a designed pattern responsive to irradiation by light, and wherein the photoelectron beam is passed through an elongated slit defined in an electrode plate, said method comprising the steps of:

• applying an electrical field and a magnetic field between said photoelectron mask and said plate such that the photoelectron beam emitted from said photoelectron mask is focused on said object;
• irradiating the photoelectron mask with an optical beam having an elongated cross-section so that said mask emits a photoelectron beam having a correspondingly elongated cross-section which coincides with the shape of the elongated slit in the electrode, said emitted beam being projected in a general direction toward the object;
• maintaining the object at an electrical potential level such that the electrical potential level of the object is identical to the electrical potential level of the electrode plate;
• causing the photoelectron beam to pass through the elongated slit in the electrode plate;
• and
• moving the photoelectron mask and the object relative to the electrode plate and the optical beam in planes that are perpendicular to the general direction of the photoelectron beam and in directions that are perpendicular to elongated dimension of the cross-section of the photoelectron beam.