Abstract: Embodiments of the invention provide a thin film magnetic head suitable for high density recording having a small erase band ?E and a small fringe magnetic field, and a large recording magnetic field. In one embodiment, a width LW of a lower magnetic pole piece protuberance of a leading side magnetic pole piece, at a face in contact with a write gap layer, is made smaller than a width TW of an upper magnetic pole piece front layer of a trailing side magnetic pole piece, at a face in contact with the write gap layer, and the width of the lower magnetic pole piece protuberance adjacent to the write gap layer is made larger, in a direction from the write gap layer.

Abstract: Embodiments of the invention provide a thin film magnetic head suitable for high density recording having a small erase band ?E and a small fringe magnetic field, and a large recording magnetic field. In one embodiment,a width LW of a lower magnetic pole piece protuberance of a leading side magnetic pole piece, at a face in contact with a write gap layer, is made smaller than a width TW of an upper magnetic pole piece front layer of a trailing side magnetic pole piece, at a face in contact with the write gap layer, and the width of the lower magnetic pole piece protuberance adjacent to the write gap layer is made larger, in a direction from the write gap layer.

Abstract: A semiconductor device has a strongly bonding structure for improving bond strength between the semiconductor and the insulating layer even if the insulating layer is formed by a traditional method which causes slight damage to the semiconductor. The strongly bonding structure includes an oxide layer 12 (containing a constituent element of the semiconductor), an oxide bonding layer, a bond-creating layer (which may disappear from the finished product), and an insulating layer, which are sequentially formed one over the other. The oxide layer may be either one which occurs naturally or one which is formed artificially. The oxide bonding layer is formed by reaction between oxygen in the oxide layer and a constituent element in the bond-creating layer. The bond-creating layer contains an element that oxidizes and an element that reacts with a constituent element of the insulating layer.