Method for producing flat composite semiconductor substrates

Claim 1

A method for the production of a substantially flat semiconductor structure said structure consisting of a lattice substrate and first, second and third epitaxially grown thin films, said lattice substrate consisting of the elements A and B, said first, second and third films respectively consisting of the elements A, B and C, where A, B and C are respectively different elements selected from a plurality of elements and where said plurality of elements is limited to a group consisting of gallium and indium for the A elements and phosphorus and arsenic, for the B and C elements, said method comprising: epitaxially growing said first film on said lattice substrate, where said first film has the formula AB1 xCx, where x is the compositional gradient parameter having a value of approximately zero at the juncture of said first film and said lattice structure, and where x increases to a value of x1; epitaxially growing said second film on said first film where said second film has the formula AB1 xCx, where x is the compositional gradient parameter having a value of x1 at the juncture of said first and second films, and where x decreases to a value x2; epitaxially growing said third film on said second film, where said third film has the formula AB1 xCx, where x is the compositional gradient parameter and has a substantially constant value approximately equal to x3; and where x in said formula AB1 xCx may have any value greater than zero and less than one, where x1, x2 and x3 are respectively particular values of x, where x1 is between 5 and 15 percent greater than x2, and x3 is approximately equal to x2, whereby said semiconductor structure has its mechanical stresses substantially compensated thereby eliminating warping or bowing of said semiconductor structure.

Claim 2

A method for the production of composite flat epitaxial films of gallium arsenide phosphide on a gallium arsenide substrate, where said gallium arsenide phosphide has the formula Ga As1 x Px and x is less than one and greater than zero, and wherein x varies in magnitude in a non-linear relationship with respect to the sum thickness of said films, said method comprisng: growing a first epitaxial film of gallium arsenide phosphide of a first thickness on said gallium arsenide substrate and wherein x varies within said first thickness from approximately zero to approximately 0.4; growing a second epitaxial film of gallium arsenide phosphide on said first epitaxial film of gallium arsenide phosphide, where said second film has a second thickness and wherein x varies within said second thickness from approximately 0.4 to approximately 0.38; growing a third epitaxial film of gallium arsenide phosphide on said second epitaxial film of gallium arsenide phosphide, where said third film has a third thickness and wherein x is approximately 0.38 throughout said third thickness, whereby warping or bowing of the structure comprising said gallium arsenide substrate and said first, second and third epitaxial films of gallium arsenide phosphide, is eliminated.

Claim 3

A method for the production of composite flat epitaxial films of indium arsenide phosphide on a indium arsenide substrate, where said indium arsenide phosphide has the formula In As1 x Px and x is less than one and greater than zerO, and wherein x varies in magnitude in a non-linear relationship with respect to the sum thickness of said films, said method comprising: growing a first epitaxial film of indium arsenide phosphide of a first thickness on said indium arsenide substrate and wherein x varies within said first thickness from approximately zero to approximately 0.4; growing a second epitaxial film of indium arsenide phosphide on said first epitaxial film of indium arsenide phosphide, where said second film has a second thickness and wherein x varies within said second thickness from approximately 0.4 to approximately 0.38; growing a third epitaxial film of indium arsenide phosphide on said second epitaxial film of indium arsenide phosphide, where said third film has a third thickness and wherein x is approximately 0.38 throughout said third thickness, whereby warping or bowing of the structure comprising said indium arsenide substrate and said first, second and third epitaxial films of indium arsenide phosphide is eliminated.

Claim 4

A method for producing a substantially flat semiconductor structure comprising first, second and third epitaxial films of gallium arsenide phosphide on a gallium arsenide substrate, where the composition of said gallium arsenide phosphide films each has the formula Ga As1 xPx and where x has the range of less than one and greater than zero, said method comprising: epitaxially growing said first film of gallium arsenide phosphide on said gallium arsenide substrate with x equal to approximately zero at the juncture of said first film and said gallium arsenide substrate and x equal to a value x1 at the surface of said first film, and where x1 is equal to or greater than 0.4 and less than one; epitaxially growing said second film of gallium arsenide phosphide on said first film with x equal to approximately x1 at the juncture of said first and second films and x equal to a value x2 at the surface of said second film, and where x2 is less than x1 and greater than 0.3; epitaxially growing said third film of gallium arsenide phosphide on said second film with x having a substantially constant value x3 throughout the thickness of said third film, where x3 is approximately equal to x2, whereby warping or bowing of said semiconductor structure, due primarily to a mismatch in lattice parameters, is eliminated.

Claim 5

A method for producing a substantially flat semiconductor structure comprising first, second and third epitaxial films of indium arsenide phosphide on a indium arsenide substrate, where the composition of said indium arsenide phosphide films each has the formula Ga As1 xPx and where x has the range of less than one and greater than zero, said method comprising: epitaxially growing said first film of indium arsenide phosphide on said indium arsenide substrate with x equal to approximately zero at the juncture of said first film and said indium arsenide substrate and x equal to a value x1 at the surface of said first film, and where x1 is equal to or greater than 0.4 and less than one; epitaxially growing said second film on indium arsenide phosphide on said first film with x equal to approximately x1 at the juncture of said first and second films and x equal to a value x2 at the surface of said second film, and where x2 is less than x1 and greater than 0.3; epitaxially growing said third film of indium arsenide phosphide on said second film with x having a substantially constant value x3 throughout the thickness of said third film, where x3 is approximately equal to x2, whereby warping or bowing of said semiconductor structure, due primarily to a mismatch in lattice parameters, is eliminated.

Claim 6

A method fOr producing a substantially flat semiconductor structure having at least first, second, and third epitaxial films of gallium arsenide phosphide on a semiconductor substrate of gallium arsenide, said first, second, and third films of gallium arsenide phosphide being grown upon, in the order recited, said gallium arsenide substrate, and where the formula for gallium arsenide phosphide for each of said films is Ga As1 x Px, where x is the compositional gradient parameter and may have any value less than one and greater than zero, said method comprising: growing said first epitaxial film of gallium arsenide phosphide on said gallim arsenide semiconductor substrate in a manner such that the compositional gradient parameter x increases linearly with respect to the thickness of said first epitaxial film; growing said second epitaxial film on said first epitaxial film in a manner such that the compositional gradient parameter x decreases linearly with respect to the thickness of said second epitaxial film; growing said third epitaxial film on said second epitaxial film in a manner such that the compositional gradient parameter x is substantially constant throughout the thickness of said third film, wherein the final value of x for the first epitaxial film is between 5 and 15 percent greater than the value of x for the third epitaxial film, whereby warping, or bowing, of said semiconductor structure is eliminated.

Claim 7

A method for producing a substantially flat semiconductor structure having at least first, second and third epitaxial films of indium arsenide phosphide on a semiconductor substrate of indium arsenide, said first, second, and third films of indium arsenide phosphide being formed upon, in the order recited, said indium arsenide substrate, and where the formula for indium arsenide phosphide for each of said films is In As1 x Px, where x is the compositional gradient parameter and may have any value less than one and greater than zero, said method comprising: growing said first epitaxial film of indium arsenide phosphide on said indium arsenide semiconductor substrate in a manner such that the compositional gradient parameter x increases linearly with respect to the thickness of said first epitaxial film; growing said second epitaxial film on said first epitaxial film in a manner such that the compositional gradient parameter x decreases linearly with respect to the thickness of said second epitaxial film; growing said third epitaxial film on said second epitaxial film in a manner such that the compositional gradient parameter x is substantially constant throughout the thickness of said third film, wherein the final value of x for the first epitaxial film is between 5 and 15 percent greater than the value of x for the third epitaxial film, whereby warping, or bowing, of said semiconductor structure is eliminated.