Device for forming nanostructures on the surface of a semiconductor wafer by means of ion beams

The invention makes it possible to develop the devices for producing nanostructures which are used for manufacturing the semiconductor items having high resolution optical instruments. The inventive device comprises a vacuum chamber provided with a pumping and annealing system, a unit for introducing the semiconductor wafers into the chamber, a controllable energy ion source, a mass-separator, an electron detector, a holder for the semiconductor wafer, a device for measuring the ion current, a quadrupole mass-analyzer and a computer provided with a monitor and interface. Axes of column of the ion beam transportation, an optical microscope and electron projector are arranged on the same plane as a normal line to the semiconductor wafer in a working position thereof and intercross at the same point on the front face of the wafer. An optical microscope and electron projector are arranged on the front face of the wafer and have a minimal angle therebetween.

BEST IMPLEMENTATION OPTION The technical result to be obtained from implementing the invention is production of thin-film semiconductor structures suitable for creating new-generation semiconductor devices and diffracting screens. This result can be achieved as follows. Wafer 3 is placed in the vacuum chamber 1 with a residual pressure of 5-10 −10 torr. A column source of the duoplasmatron type is filled with nitrogen to generate a nitrogen ion flow. The ion flow energy and wafer radiation angle values are set. An area of S&equals;200×200 sq. &mgr;m on the wafer surface is evenly irradiated with a nitrogen ion flow under a current of I&equals;250 nA. The following conditions are to be met. The axis of the ion beam transport column 7 , the optical microscope 8 , and the electron gun 9 must intersect in one point F located on the front side of the wafer 3 surface. This point must be the focal point of the ion beam transport column 7 , the optical microscope 8 , and the electron gun 9 . The ion beam transport column 7 , the optical microscope 8 , and the electron gun 9 must be located on the front side of the wafer, and the angle between them must have the minimum value. The ion source 5 is a duoplasmatron-type source operating on such gases as argon, oxygen and nitrogen, and providing ion energy values in the range of 500 eV to 20 keV. The mass separator 6 is a mass separator with a mass range from 1 to 100 a.e.m., and has a relative mass resolution of 5 a.e.m. The ion beam transport column 7 provides for changing the raster size and the raster side ratio. The ion beam diameter must be about 1 &mgr;m (from 0.9 &mgr;m to 1.5 &mgr;m) with an ion energy value of 5 keV. The X and Y directions of the ion beam scanning must coincide with the movement directions of the wafer holder 12 . The electron control of the ion beam shift along the Y axis must not be less than the double raster size in the Y direction. The ion beam sweep linearity in the Y direction must be controlled. The optical microscope 8 is made with wafer highlight, an 8-100-time magnification, and image display on the TV monitor. The electron gun 9 creates an electron energy value of 100 eV to 10 keV, an electron beam current of 5 &mgr;A, and spot size of about 100 nm. The X and Y ion beam scanning directions must coincide with the movement directions of the wafer holder 12 . The electron control of the ion beam shift along the Y axis must not be less than the double raster size in the Y direction. The ion beam sweep linearity in the Y direction must be controlled. The quadrupole mass analyzer 10 is equipped with the optics for gathering both positive and negative secondary ions. The range of measured masses is from 1 to 100 a.e.m. The absolute mass resolution is 5 a.e.m. The electron detector 11 is a detector of secondary electrons. The wafer holder 12 provides for wafer inclination in such a way that the normal to the wafer remains on the plane of the axes of the ion beam transport column 7 , the optical microscope 8 , and the electron gun 9 . The inclination angle of the wafer normal to the ion beam transport column 7 axis must be from 0 to 90°. The wafer rotation must be from 0° to 360°. There is no need for continuous rotation. The angle precision must be ±0,5°. The wafer holder should provide for heating the wafer from the room temperature to 700° C. The X and Y wafer movement directions should lie on the wafer plane. The wafer movement in the Z direction should provide for superposing the wafer surface plane with the focal point of the ion beam transport column 7 , the optical microscope 8 , and the electron gun 9 . The wafer movement error should be about 1 &mgr;m. The ion current meter 13 provides for measuring the current from the wafer. The computer 14 with monitor 15 and interface 16 are designed for controlling the whole unit. The computer 14 scans the ion beam through a set of sites by moving the wafer along the given site coordinates, while the stopping of the ion beam should be defined by the wafer current integral, as well as by the signal of certain ions detected by the quadrupole mass analyzer 10 . The computer provides for receiving wafer surface images both in secondary electrons generated by the scanning electron or ion beams, and through the optical microscope 8 , to superpose the ion and electron beam rasters on the wafer surface. 
 INDUSTRIAL APPLICATION This invention refers to the sphere of electronic and vacuum technology, in particular to the units for the formation of various structures and coatings on semiconductor wafers. It can be used to develop new-generation semiconductor devices, as well as in optical instrument-making. The invention can be used to create units for production of nanostructures suitable for making semiconductors with a high integration level, and high-resolution optical devices.