Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
77 words
Appartus for use in a semiconductor annealing process CHARACTERISED BY components of black-body material stable under annealing conditions, said components including a base (10), an annular guard ring (11) and a lid (12) such that when the guard ring is positioned on the base and the lid is positioned on the guard ring, the components form a container (hereinafter referred to as a "black-box") containing a cavity for fully enclosing a semiconductor wafer (1) to be annealed.
Claim 2
Dependent Claim
77 words
Appartus for use in a semiconductor annealing process CHARACTERISED BY components of black-body material stable under annealing conditions, said components including a base (10), an annular guard ring (11) and a lid (12) such that when the guard ring is positioned on the base and the lid is positioned on the guard ring, the components form a container (hereinafter referred to as a "black-box") containing a cavity for fully enclosing a semiconductor wafer (1) to be annealed.
Claim 3
Dependent Claim
15 words
Apparatus as claimed in claim 1 in which said black-body material comprises graphite or silicon.
Claim 4
Dependent Claim
32 words
Apparatus as claimed in claim 1 or claim 2 in which surfaces of the said components which constitute the internal surfaces of the black-box are encapsulated with a layer of encapsulating material.
Claim 5
Dependent Claim
37 words
Apparatus as claimed in claim 3 in which said encapsulating material is selected from the group consisting of phosphosilicate glass, borosilicate glass, SiO₂, and a glass consisting of 3% B₂,O₃, 1% Al₂O₃ and 96% SiO₂ by weight.
Claim 6
Dependent Claim
19 words
Apparatus as claimed in claim 4 in which the encapsulating material comprises phosphosilicate glass comprising 2-10 mole percent P₂O₅.
Claim 7
Dependent Claim
43 words
A semiconductor fabrication process comprising subjecting a semiconductor wafer to an annealing procedure CHARACTERISED IN THAT the annealing procedure is carried out with the wafer enclosed in the cavity of a black-box constituted by apparatus as claimed in any of the preceding claims.
Claim 8
Dependent Claim
17 words
A process as claimed in claim 6 wherein the annealing procedure is a rapid thermal anneal (RTA).
Claim 9
Dependent Claim
78 words
A process as claimed in claim 7 in which said RTA includes in sequence, a pre-anneal step, a main annealing step, and a post-anneal step, the pre-anneal step being conducted at a temperature and for a period sufficient to reduce any thermal shock to the semiconductor material which may result from the main-annealing step, and the post-anneal step being conducted at a temperature and for a period sufficient to relieve stresses which may result from the main-annealing step.
Claim 10
Dependent Claim
117 words
A process as claimed in claim 8 in which said compound semiconductor material comprises GaAs, said RTA includes exposure of the black-box with the wafer therein in succession to the pre-anneal step in the temperature range 625 to 675 0 C for a period in the range 20 to 40 seconds, the main annealing step at a peak temperature within the range 900 to 1000 0 C for a period in the range 5 to 20 seconds, and the post-anneal step in the temperature range 825 to 875 0 C for a period in the range 25 to 35 seconds, followed by cool down at a rate in the range 5 to 50 0 C per second.
Claim 11
Dependent Claim
22 words
A process as claimed in claim 9 in which said cool-down is at a rate not exceeding 30 0 C per second.
Claim 12
Dependent Claim
22 words
A process as claimed in claim 10 in which said cool-down is at a rate of about 10 0 C per second.
Claim 13
Dependent Claim
70 words
A process as claimed in any of claims 6 to 11 wherein the wafer has dopant ions implanted into at least one selected area of at least one surface thereof and a layer of encapsulating material (2) over said surface, said annealing procedure being conducted at a temperature and for a period sufficient to remove damage caused to the said surface by the implantation and to activate said dopant ions.
Claim 14
Dependent Claim
39 words
A process as claimed in claim 12 in which said encapsulating material on said wafer surface comprises a glass selected from phosphosilicate glass, borosilicate glass and a glass consisting of 3% B₂O₃, 1% Al₂O₃ and 96% SiO₂ by weight.
Claim 15
Dependent Claim
24 words
A process as claimed in claim 13 in which said encapsulating material on said wafer surface comprises phosphosilicate glass comprising 2-10 mole percent P₂O₅.