Semiconductor device and method of producing the same
AssigneeHitachi, Ltd.
InventorHiroshi Fukuda
Life of this patent
Estimating the term…
Abstract
Exposure is performed by using a phase shifting mask having a constant shifter line width L in the direction of transistor gate length Lg, thereby forming a designed transistor gate pattern in a part of a shifter edge of the phase shifting mask and forming a dummy gate pattern which has the same device structure as that of the transistor gate but does not have a circuit function in the rest of the shifter edge so as to be isolated from the transistor gate pattern. By the operation, the minimum distance between each of all of the transistor gate patterns in an active region and each of the dummy gate patters is set to be substantially constant.
Claims9
A method of producing a semiconductor device comprising:
- (1) a step of designing a transistor gate pattern in a predetermined region where transistor gates exist in a semiconductor device so as to be centered on predetermined lines of a lattice, and performing multiple-exposure on a resist film formed on a semiconductor substrate by using:
- a first alternating phase shifting mask including phase shifters between successive lines of the lattice, the phase shifters having a width substantially equal to a pitch of the lattice in the region and disposed so that an edge of the phase shifters substantially coincide with a line of a desired transistor gate pattern;
- and a second mask in which a region including the transistor gate pattern and a dummy gate pattern isolated from the transistor gate pattern on the lattice in the region is used as a light shielding region;
- (2) a step of developing the resist film to thereby form resist patterns;
- and
- (3) a step of etching a film to be processed on the semiconductor substrate by using the resist patterns as a mask;
- wherein the shifter line width L of the phase shifting mask is 2λ/(NA×M) or smaller, where M is a reduction ratio of optics used for exposure, and wherein an amplitude of variation in the shifter line width L lies within ±10%.
A method of producing a semiconductor device comprising,
- a step of forming a circuit pattern block having fine line patterns by multiply exposing a phase-shifting mask including phase-shifting light transmitting apertures in an opaque region, and a binary mask including a light transmitting region and an opaque region onto a resist film formed on the semiconductor device substrate,
- wherein said fine line patterns have different respective distances to adjacent ones of said fine line patterns, wherein said fine line patterns are formed in regions of the resist film corresponding to areas between pairs of light transmitting apertures with reversed phase transmission on the phase-shifting mask, and
- wherein a variation in width of said light transmitting apertures in a direction normal to the fine line patterns formed between each adjacent pair of apertures being within ±10% in the circuit pattern block.
A method of producing a semiconductor device comprising,
- a step of forming a circuit pattern block having fine line patterns by multiply exposing a phase-shifting mask including phase-shifting light transmitting apertures in an opaque region, and a binary mask including a light transmitting region and an opaque region onto a resist film formed on the semiconductor device substrate,
- wherein said fine line patterns have different respective distances to adjacent ones of said fine line patterns, wherein said fine line patterns are formed in regions of the resist film corresponding to areas between pairs of light transmitting apertures with reversed phase transmission on the phase-shifting mask,
- wherein at least one additional light transmitting aperture is placed next to at least one of two apertures in the aperture pairs for forming the fine line patterns, so as to achieve alternating change in phase transmission for the additional aperture and the pairs of apertures, so that optical image characteristics are substantially the same for the fine line patterns with different distances to adjacent patterns, and
- wherein a shifter line width L of the phase shifting mask is 2 λ/(NA×M) or smaller, where M is a reduction ratio of optics used for exposure, and wherein an amplitude of variation in the shifter line width L lies within ±10%.
Dependencies are inferred from the claim text.